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Sacrificing Accuracy For Speed and Efficiency In Processors

Skudd writes "Modern computing has always been reliant on accuracy and correct answers. Now, a professor at Rice University in Houston posits that some future applications could be revolutionized by 'probabilistic computing.' Quoting: 'This afternoon, Krishna Palem, speaking at a computer science meeting in San Francisco, will announce results of the first real-world test of his probabilistic computer chip: The chip, which thrives on random errors, ran seven times faster than today's best technology while using just 1/30th the electricity. ... The high density of transistors on existing chips also leads to a lot of background "noise." To compensate, engineers increase the voltage applied to computer circuits to overpower the noise and ensure precise calculations. Palem began wondering how much a slight reduction in the quality of calculations might improve speed and save energy. He soon realized that some information was more valuable than other information. For example, in calculating a bank balance of $13,000.81, getting the "13" correct is much more important than the "81." Producing an answer of $13,000.57 is much closer to being correct than $57,000.81. While Palem's technology may not have a future in calculating missions to Mars, it probably has one in such applications as streaming music and video on mobile devices, he said.'

499 comments

  1. Bank balance by johnny+cashed · · Score: 5, Funny

    And $81,000.31 is a much more correct answer!

    1. Re:Bank balance by CastrTroy · · Score: 4, Insightful

      I agree. The whole problem with the example given in the summary is that your bank balance should never be wrong. There is no room for error in calculating bank balances. I also don't want to hear skips and pops in my music because they though it would be more energy efficient to use a processor that produced errors. I already get 26 hours of charge out of my MP3 player. I'd rather have them focus on getting more space for cheaper so I can carry lossless audio on my portable mp3 player.

      --

      Anthropic principle: We see the universe the way it is because if it were different we would not be here to see it.
    2. Re:Bank balance by BadAnalogyGuy · · Score: 5, Insightful

      If you are listening to music on a portable media device, it's safe to say that you aren't going to be able to hear the difference between the lossy format and the lossless format.

      It's like drinking from a well. Connoisseurs may claim to be able to taste the difference between it and tap water, but that's just the extra tang from all the bull shit.

    3. Re:Bank balance by Jeff+DeMaagd · · Score: 1

      I expect financial calculations to be accurate to the penny, or even calculated to the third or fourth decimal place, then rounded to the nearest 2nd decimal place.

      But I agree, audio & video playback and other things are different. An occasional error on the 15th or 16th bit isn't going to be audible in real-world portable circumstances.

    4. Re:Bank balance by gbjbaanb · · Score: 1

      For example, in calculating a bank balance of $13,000.81, getting the "13" correct is much more important than the "81."

      not to an accountant is isn't.

      Besides, to take the example further: if getting the $800 right is much more important than the rest of the $800,000,000,000, does it mean no-one will care if my account suddenly goes from $2000 to $20,000?

    5. Re:Bank balance by moderatorrater · · Score: 2, Interesting

      I disagree. Cents is already an arbitrary cut off for the calculations' accuracy, why not just cut it off at dollars? I do my budget religiously every night and go over everything with my wife a couple of times a month. If every transaction were rounded up to the nearest dollar, it wouldn't destroy my finances. I doubt it would seriously mess up my finances if they were off by $5. Now, if I were able to give up efficiency and accuracy in my financial calculations for something else that I considered valuable (for instance, lower interest in my mortgage or my credit card payments counted for 30x what they did before), then this is something that should seriously be considered.

      With regards to music, they're not talking about skips and pops, they're talking about extremely slight modulations in pitch or, in the case of video, a very slight difference in color. If these differences are random and small enough (say, 300 per second), then it averages out to the same thing and our minds can't tell the difference. Hell, if the differences are small enough you wouldn't really notice them anyway. If I could get 30x the battery life out of my laptop by accepting imperfections in the video it displays and in the audio it plays (and I know it wouldn't, but this is a hypothetical), then I'd gladly go for it.

    6. Re:Bank balance by phoenix321 · · Score: 4, Interesting

      High accuracy is required for encoding music and video, though.

      Maybe we could have a selective accuracy, where programmers can set their needs via registers or direct it to different CPU cores. Accurate cores for banking transactions, AV-stream encoding and 2D GUI operations while inaccurate cores are used for AV-stream decoding, and computer game 3d drawing and AI decisions.

      There's a whole lot we are calculating now without the need for more than 3 significant digits - and a whole bunch where we intentionally use random numbers, sometimes even with strong hardware entropy gathering.

      These are all cases where we could just scrap the accuracy for faster processing or longer battery times. No one cares about single bit errors in portable audio decoders or in high fps 3d gaming.

    7. Re:Bank balance by Hojima · · Score: 5, Insightful

      There are countless applications for a computer that don't depend on accuracy, but do depend on speed. For example: gaming, stock analysis, scientific/mathematical research etc. Just about every use for the computer can benefit from this. Bear in mind these applications can take the hit of inaccuracy, if not benefit from it depending on the situation. Yes there are some instances were accuracy is crucial, but that's why they will continue to make both of the processors. It's what they call a free market, and there will be always be a new niche to fill.

    8. Re:Bank balance by Sancho · · Score: 1

      Cutting off at the cents place isn't arbitrary--it's done because the cent is the smallest unit of currency produced by the US.

    9. Re:Bank balance by Anonymous Coward · · Score: 0

      But, to quote a popular saying from Britain, "A Penny saved is a penny earned"
      I am sure this still applies to the Cent.
      And i would consider it doubly important in this recession.

      These kind of things would be better suited to things that don't require accuracy, like liquid measurements for foods (nobody ever gets it 100% perfect, so why try?)

    10. Re:Bank balance by ZombieWomble · · Score: 1
      The issue is, what does this CPU actually offer- specifically, how large would the loss in quality be? Would simply cutting down on the accuracy of the algorithms used to reduce its computational burden and thus the amount of processing power needed work just as well?

      There's a dearth of hard information in the article on the chip in the article (all the headline-grabbing speedup values, but no details on exactly how much accuracy is lost), but it seems to me that such a chip would really need to conclusively prove that the accuracy trade-offs cannot be just as well made at the software level as at the hardware level.

    11. Re:Bank balance by tshetter · · Score: 1

      Tell that to gas stations and their $1.909/gal price.

    12. Re:Bank balance by Sancho · · Score: 1

      I did. They agreed with my statement.

      (note that I didn't say that it was the smallest possible pricing amount.)

    13. Re:Bank balance by ZombieWomble · · Score: 2, Interesting
      Obviously this is the potential argument for these chips, but the majority of these systems have a trade-off between between speed and accuracy: Most numerical mathematical methods have a clear trade-off between speed and accuracy. It's pointless to gain speed if it pulls your accuracy down more than simply reducing the complexity of your algorithms.

      Given that, I would expect this hardware - if it proves useful - would primarily be in the "entertainment" sector of the market. Of course making this judgment is pretty much impossible at the moment as there's no real information on just how bad the accuracy loss is with these chips.

    14. Re:Bank balance by mishehu · · Score: 1

      To add to your thoughts, I also was thinking about this - how would the processor *know* what data is "more important" than other data and therefore switch between modes? Why would I want inaccurate data from a processor that "thrives on random errors" unless I'm working on building an infinite improbability drive? (And the trick to that is a very hot cup of tea, as we all know...)

    15. Re:Bank balance by Anonymous Coward · · Score: 0

      This is handled by software at the algorithm level. There are already techniques to use fixed-point or integer operations instead of floating-point to get significant speed gains.
          It should also be noted that most hardware floating point units round to some degree. Any x86 processor cannot represent .6 exactly.

    16. Re:Bank balance by memco · · Score: 4, Insightful

      Ok, so not only do I have to give up efficiency in the chip itself, but now my efficiency suffers because I now have to determine which chips are useful for which applications. I don't want to have to start thinking about whether or not I plan to use my new laptop for anything requiring accuracy greater than such and such a percentage. I suppose this might be effective for niche markets, but it seems messy if you try to make it part of all computing platforms.

      --
      Get me a meat pie floater!
    17. Re:Bank balance by poetmatt · · Score: 1

      Actually, this is the issue with "who will really have a problem".

      The answer is, just like lossless formats, there are lots of situations where you absolutely cannot have an error and an equal number of situations where it's not an issue. Especially high performance, industrial, etc settings. Example being how for a lossless codec on cheap headphones you can't hear the differencebut on serious ones it's night and day. However, those situations for fault tolerance don't necessarily go together.

      Therefore, if there becomes a way to toggle between problematic and non in a processor, that will be more beneficial than just problematic-only chipped processors. Also, it's all about the implementation. I mean not everyone uses ECC ram.

    18. Re:Bank balance by Anonymous Coward · · Score: 0

      Actually, depending upon where you live, you can taste the difference. I've been in some places where I can smell and taste the chlorine they put in the water to keep stuff from growing in it.

    19. Re:Bank balance by osu-neko · · Score: 0, Flamebait

      *psst* There's more than one chip on your laptop's motherboard. I'm sure you won't be forced into any tough decisions. The engineers who make your laptop will decide whether your FPU requires more accuracy than your DSP and MPEG decoder.

      --
      "Convictions are more dangerous enemies of truth than lies."
    20. Re:Bank balance by Anonymous Coward · · Score: 0

      Minute errors make big differences when doing the Fourier transforms necessary for mp3 decoding. The process tends to magnify small errors.

      It can be the difference between music and white noise.

      Any digital signal process using feedback (filters etc) can become unstable with errors too, which means more loud unpleasant noises.

      Anyway, even if we were dealing with uncompressed audio, I don't see how the errors could know to restrict themselves to the lower bits...

    21. Re:Bank balance by osu-neko · · Score: 1

      No, it means you've completely misunderstood the purpose of the analogy.

      --
      "Convictions are more dangerous enemies of truth than lies."
    22. Re:Bank balance by Sir_Lewk · · Score: 0, Offtopic

      Clearly you have only been exposed to some *very* nice tap water ;)

      --
      "linux is just DOS with a UNIX like syntax" -- Galactic Dominator (944134)
    23. Re:Bank balance by Anonymous Coward · · Score: 0

      Depends on your tap water. If you live in, say, southern California and claim what comes out of your tap is equivalent to pure mountain spring water, your taste buds need adjusting. That stuff reeks coming out of the tap.

      As much as I love going on vacation in the south west US, within the first week the one thing I long for is coming home to water that doesn't make me feel like taking a shower as I step out of the shower.

      As far as the actual topic is concerned, I guess it depends on how predictable the inaccuracies are. It could be a useful concept under some circumstances.

    24. Re:Bank balance by UltraAyla · · Score: 1

      But that choice of having it be the smallest unit IS "arbitrary" in some sense even if there is reason behind it. We could add some other unit after it and have a whole new fraction of currency. He's saying he doesn't care about the cents portion. Not enough of his transactions make use of it where if everything was rounded up to a higher number, it's not a problem

    25. Re:Bank balance by Hognoxious · · Score: 1

      I'm amazed how many people here - who you'd expect to understand concepts like units - trot out this old tale.

      A price is x units of currency per y units of stuff. It isn't an amount. To get an amount you multiply it by the quantity purchased. This amount is always rounded to 2 decimal places of dollars.

      That's why you don't get out a hacksaw and start sawing pennies up when you pay cash. That's why if you pay by card, the amount charged to it is also to 2 dp of dollars.

      --
      Confucius say, "Find worm in apple - bad. Find half a worm - worse."
    26. Re:Bank balance by Tuoqui · · Score: 2, Interesting

      Well the odds are you probably wouldn't even notice if a few bits here and there were wrong in your audio stream. I'm not sure what the error rate is but if its less than 17 times as much as we have now it'd be worth considering for some applications

      I figure if they do use this technology they'd more than likely use the multi-core system currently in place and make one a high accuracy CPU while the other 2-4 cores high speed CPUs. Like someone said it'd be used for gaming and streaming video/audio where 'accuracy' isnt as important.

      --
      09F911029D74E35BD84156C5635688C0
      +2 Troll is Slashdot's way of saying groupthink is confused
    27. Re:Bank balance by Anonymous Coward · · Score: 0

      If you allow for the randomness only as a small fraction of the smallest entry to be tallied, it wouldn't be much of a problem. I don't know what the smallest entry recorded in banking is, the interest accrued in 1 month? A service charge? If your $2000 account accrues something on the order of $5 in one month, it wouldn't be much of a problem if (using your $800,000,000,000 figure....800 billion dollars?, really? Guess you are using the US bailout figure) instead of awarding you $5.0000000000000, it awarded $5.0000000000625

    28. Re:Bank balance by Anonymous Coward · · Score: 0

      Almost every definition I've heard for the word "arbitrary" indicates that reason isn't used. The original poster certainly implied that there was no reason to round to cents over another decimal place.

      By your definition, everything in the world is arbitrary. The point of using the word is to imply a lack of rationale behind the decision.

    29. Re:Bank balance by Nebu · · Score: 1

      Cutting off at the cents place isn't arbitrary--it's done because the cent is the smallest unit of currency produced by the US.

      But it might not be for long; see Microtransaction.

    30. Re:Bank balance by Teun · · Score: 1
      Don't get upset about a cent.
      In NW Europe the cent has all but disappeared from the shops, for example in Finland they haven't even bothered to mint them when the euro came about and in The Netherlands shops routinely display a sticker stating they round up/off to the nearest 5 cents for cash transactions (cash is the exception anyway).
      Because these small differences work out to be neutral over several bills no-one is complaining but instead all are happy with the time saved at the check out.

      Now if some mathematician can make a water tight case the low-power process is going to be neutral over a larger number of transactions i don't see a problem, even in private finances with say a 5 nines accuracy.

      --
      "The likes of Facebook and WhatsApp are free to those whose privacy is of zero value."
    31. Re:Bank balance by Anonymous Coward · · Score: 0

      As a related note, a cent also equals a dollar.

    32. Re:Bank balance by Nebu · · Score: 1

      With regards to music, they're not talking about skips and pops, they're talking about extremely slight modulations in pitch or, in the case of video, a very slight difference in color. If these differences are random and small enough (say, 300 per second), then it averages out to the same thing and our minds can't tell the difference. Hell, if the differences are small enough you wouldn't really notice them anyway. If I could get 30x the battery life out of my laptop by accepting imperfections in the video it displays and in the audio it plays (and I know it wouldn't, but this is a hypothetical), then I'd gladly go for it.

      Not to mention that the vast majority of people (I'd easily wager for 99% or higher) store their music in a lossy format such as mp3, so they are already experiencing small random errors.

      I'd wager an even higher proportion of people (99.99%?) store their video in a lossy format. In fact, while I have no problem naming lossy video compression schemes (DivX/XviD, Mpeg-4, Ogg Theora, Indeo, Quicktime, etc.), I can't come up with a single lossless video codec besides "raw".

    33. Re:Bank balance by Anonymous Coward · · Score: 1, Insightful

      "There are countless applications for a computer that don't depend on accuracy, but do depend on speed. For example: gaming, stock analysis, scientific/mathematical research etc."

      Any mathematical calculation which is then used to decide program flow will result in errors. That directly affects gaming, stock analysis, scientific/mathematical research.

      Also chaos theory applies, which can amplify some errors over time as the values propagate. This greatly complicates the problems in real world examples.

      Arguing accuracy doesn't matter isn't the case in real world examples. In simply lab experiments its much easier to control the chaotic behavior. Achieving predictable and repeatable ways in real world examples is a lot harder.

    34. Re:Bank balance by Sancho · · Score: 1

      I didn't read the entire article, but I did skim it. Did I miss the part where the US would be printing/minting currency under a penny?

    35. Re:Bank balance by Teun · · Score: 1

      not to an accountant is isn't.

      Hmm, here in The Netherlands the tax man rounds up/off the next full euro.

      Meaning it all depends on the standards you set.
      As long as it's proven the lack of absolute accuracy is within the accepted limits and neutral I see no problems.

      --
      "The likes of Facebook and WhatsApp are free to those whose privacy is of zero value."
    36. Re:Bank balance by Anonymous Coward · · Score: 0

      For example, in calculating a bank balance of $13,000.81, getting the "13" correct is much more important than the "81."

      not to an accountant is isn't.

      Yes, to an accountant it is. An accountant will be happy with even a tiny business rounding its financial accounts to the nearest dollar. Bigger companies will round to thousands, tens of thousands etc. Because 'materiality' is a key accounting concept - it doesn't matter if figures aren't perfect. In fact the nature of accountancy means that figures never will be perfect beyond utterly trivial transactions. There's a whole mass of estimates and provisions going on, plus thousands of transactions accumulated through fallible human operations.

      So ask your accountant if he'll sign off on your revenue rounded to $13,000 instead of $13,000.81 and he'll be happy to. Ask him if he minds a key figure being $18,000 instead of $13,000 and you'll get a different answer. Emphasis on key figure - if your balance sheet is i the billions then he won't care if you round the thousands.

      That doesn't mean that an accountant won't care if your computer is innacurate. But an accountant who doesn't agree that 'in calculating a bank balance of $13,000.81, getting the "13" correct is much more important than the "81."' is fucking incompetent.

    37. Re:Bank balance by ZorinLynx · · Score: 1

      You can't really round off cents in transactions on a regular basis, because then folks will use this to try to game the system.

      For instance, say it were required by law for all transactions to be rounded to the nearest dollar. Don't think retailers will adjust prices so that cents in the totals tend to come out to .50 or more before rounding?

      And I'm fairly certain your paycheck will be something like $xxxx.49 before rounding. ;)

    38. Re:Bank balance by Anonymous Coward · · Score: 0

      This is quite off topic, but different water sources really do have dramatically different flavors. Having lived in a number of places I can tell you that Chicago tap water tastes pretty neutral(probably due to heavy processing), southern New Jersey tap water actually tastes pretty good, though I don't know where it comes from, Florida tap water is just awful tasting, and tap water in British Columbia actually tastes better (and is cleaner) than bottled water. Well water can taste better or worse than tap water depending on local geography and potential contaminants.

      Actually, I agree with you about the portable media player issue, but you've got no idea what you're talking about when it comes to water!

    39. Re:Bank balance by wik · · Score: 2

      There's rounding in virtually every transaction you already encounter. Do you live in a location with sales tax?

      In pay periods where my paycheck is mathematically supposed to be consistent, it also fluctuates by a cent sometimes. The value averages out but there's still rounding and it's quite obvious.

      --
      / \
      \ / ASCII ribbon campaign for peace
      x
      / \
    40. Re:Bank balance by mdarksbane · · Score: 2, Interesting

      There are a few areas where games care a little bit about accuracy. You've got to be really careful about it in any kind of flight game with playing fields of more than a few miles in size. It's amazing the kind of graphical artifacts you can get if you don't take the error in floating points into account when you handle that sort of thing. In our first naive implementation of the engine, at around 50 kilometers out every character would jitter constantly every time they moved because of the last floating point bits being inaccurate.

    41. Re:Bank balance by Pentium100 · · Score: 1

      I can't come up with a single lossless video codec besides "raw".

      HuffYUV

    42. Re:Bank balance by dgatwood · · Score: 1

      Depends on what part of the FFT calculation, but sure. That said, what I'd be more concerned about is an assembly language instruction in the language of your choice along these lines: "Jump to address (0x31000 + value of register 1)". Make an off-by one in that calculation and you probably wedge the chip, or at best, get completely useless operation....

      For something like this to even be plausible, it would have to be in some very special-case vector pipeline like a GPU, not in a general-purpose CPU with jumps and branches and stuff. I'm really not convinced this has any practical use in a general-purpose CPU, randomness in quantum computing notwithstanding.

      --

      Check out my sci-fi/humor trilogy at PatriotsBooks.

    43. Re:Bank balance by Nebu · · Score: 1

      I didn't read the entire article, but I did skim it. Did I miss the part where the US would be printing/minting currency under a penny?

      I don't think the article ever says microtransactions exist, but that doesn't microtransactions don't exist.

      I am not claiming that the US will print/mine currency under a penny, but I am claiming that the cent is not the smallest unit of currency produced by the US. Here I am using the term "produce" in the sense of "causing to exist" in as "the new law produced many complaints". Microtransactions involves US currency smaller than 1 cent.

      That said, the US did produce physical currency smaller than a cent. See Mill.

    44. Re:Bank balance by dgatwood · · Score: 1

      As for the question of how to make only the lowest order bits have errors... analog computing, I guess. :-D

      That said, I just thought of one way this might be useful. If (and only if) the amount of die shrinkage and processor speed increase you can get as a result of doing this is significantly more than a factor of three and the probability of an error is significantly less than a one-in-three chance, you could use a voting algorithm with "no two alike forces retry" logic. That said, I wouldn't hold my breath on getting such high boosts and still being able to make those sorts of probability guarantees.

      --

      Check out my sci-fi/humor trilogy at PatriotsBooks.

    45. Re:Bank balance by ABasketOfPups · · Score: 0, Offtopic

      While you're correct about the portable media device, you can test people on tap water versus non-tap water and find some that clearly know when they're drinking tap water. (Chicago, for instance, has enough chlorine in the water that I'd be stunned if you couldn't tell.) Now, bottled water that was from a tap but has the chlorine filtered out, versus some heavily mineral-laden water? That's tougher. But claiming bullshit because you don't (or maybe can! but haven't tried) taste any difference between tap and well water is assuming more about other people than is justified.

    46. Re:Bank balance by shaitand · · Score: 4, Informative

      'It's like drinking from a well. Connoisseurs may claim to be able to taste the difference between it and tap water, but that's just the extra tang from all the bull shit.'

      Probably not the best example. Humans have an amazing ability to taste very minute differences in water. My TDS meter tells me that tap water here is extremely pure to begin with, but I can pick the same that has undergone carbon and ro filtering versus straight tap water in a blind taste test with 100% accuracy. I'm certainly no connoisseur.

      Actually, I'm from rural Illinois, and all the water be it tap or properly maintained well is fairly sweet there with minimal filtering. Actually the streams there are a bit muddy tasting but the water itself is sweet as it flows. It definitely beats this Florida swap water. I tasted unfiltered Florida well water once (most Florida wells have filters built in) and I vomited. The tap water here won't make you sick and it isn't that nasty but it still tastes funky.

      That said, I doubt I could tell the difference between tap, well, Illinois, or Florida water that has had that additional filtering (Carbon and Reverse Osmosis, any of those machines for $0.39/gallon at the grocery store will do). My TDS meter shows a difference in purity even from one dispensing machine to the next, but I can't taste that difference. Whatever minerals survive that process are probably pretty much the same anywhere and taste good. That filtered water tastes better than any of the unfiltered waters.

    47. Re:Bank balance by Hojima · · Score: 1, Insightful

      Given that, I would expect this hardware - if it proves useful - would primarily be in the "entertainment" sector of the market.

      Not really. Any simulations that are influenced by natural chaos would greatly benefit from this. Examples include engineering simulations of products that must have robust preventions of system failures, pharmaceutical simulations of chemical reactions that may have natural anomalies, statistical research that depends on many unknowns, stalk market predictions that depend on such statistical research, evolutionary algorithms that thrive on error, and it can even serve as supplemental calculation for AI to learn how to deal with new and unexpected occurrences. Like I said this processor has a whole new niche of its own, and it may come standard in a pc like the GPU.

    48. Re:Bank balance by shaitand · · Score: 2, Insightful

      Don't forget there are errors in the hardware processes anyway and error correction algorithms running on the software side that take care of them.

    49. Re:Bank balance by commodore64_love · · Score: 1

      I just want to add that cents quickly become dollars. Every time I use my card, I get one penny per dollar spent, 3 pennies per gasoline/food dollar spent. In just two months time, that added-up to a $50 check which they mailed me yesterday. So no I don't want to ignore the pennies and calculate at the dollar level. It would be costly.

      Trivia

      - One dollar is a measure of gold, in terms of weight. One dollar of gold == 25.8 grains of gold == about 45 pieces of Federal Reserve Notes (paper dollars). The politicians have slowly but surely devalued our money to 1/45th its value in 1933.

      --
      "I disapprove of what you say, but I will defend to the death your right to say it." - historian Evelyn Beatrice Hall
    50. Re:Bank balance by Anonymous Coward · · Score: 0

      Worst. Analogy. Ever.

      While I agree with you about lossy vs. lossy formats, if you can't taste the difference between well water and chlorinated city tap water, there is something wrong with your sense of taste.

    51. Re:Bank balance by Anonymous Coward · · Score: 0

      It's like drinking from a well. Connoisseurs may claim to be able to taste the difference between it and tap water, but that's just the extra tang from all the bull shit.

      Heavens, man, just what world do you live in?

      Yeah, the claims that some people make about differences in taste (of just about anything) are ridiculous. But it's just as ridiculous to claim that everything tastes exactly the same, because it isn't *true*.

      Oh, sure, I hear you say, it's just water, how can it taste different? But here's the secret: what you're drinking is not just pure H2O, it contains other stuff, to varying degrees.

      If you're still not convinced, let me put it this way: would you rather eat a hamburger with fries at McDonald's or at a decent restaurant? Well, maybe you even prefer McDonald's, and that's fine, but certainly you wouldn't say that there's literally going to be no difference.

      The fact that some people are snobs doesn't mean that everything's the same.

    52. Re:Bank balance by dargaud · · Score: 1

      There's a whole lot we are calculating now without the need for more than 3 significant digits

      Yes, this article is hardly news. Good programmers will choose the data type that fit the requirements without needless waste. Float or double ? Well, if you just want to store a pH, you don't need 64 bits. It will use half the memory, half the processing power and be faster (well, no longer as math cores are now optimized only for doubles and compute floats as doubles, but it used to be true). Same thing for long, short and char.

      --
      Non-Linux Penguins ?
    53. Re:Bank balance by tftp · · Score: 1

      From accounting POV he is right. Numbers in accounting are added in several ways, the simplest is horizontally (forming a column) and vertically (forming a row.) Sum of numbers in that column must be equal to sum of numbers in that row, or else something is wrong and you must find and fix it. There are, of course, more complex, though obvious tabulations - to pick one, the sum of all c/c expenses of your employees should match the number that you paid to the bank (and that should match the number that the bank wanted you to pay) - or else some of your employees may be getting richer than you think they ought to be. In business accounting numbers become large, and that's one of reasons why floating point is not welcome in these formulas. If you are a bank you must account for billions of monetary units, adding and removing very little in millions of transactions, and your end balance must be exact all the time. If you have an uncertainty of computation you can't even find where the error occurred, how large it is, and each time you recalculate you get a different answer...

    54. Re:Bank balance by godrik · · Score: 1

      There's a whole lot we are calculating now without the need for more than 3 significant digits - and a whole bunch where we intentionally use random numbers, sometimes even with strong hardware entropy gathering.

      mmm, yes you generally don't need more than 3 significant digit on the final result. But all the intermediate computation need to be more accurate to reach a 3 digit accuracy at the end. Think about a computation such as X - Y. If X and Y have the 3 first same digit, then you will have 0 significant bit for the result.

      if you do anything more complicated than adding and multiplying, then you need accurate computation.

    55. Re:Bank balance by Anonymous Coward · · Score: 0

      I think that the whole point is that the increase in speed probably does make up for the loss in accuracy, meaning that a floating point unit that allows for some errors will provide higher accuracy than a conventional FPU by doing more calculations in less time and thus getting higher accuracy.

      We will find out soon, because this is probably the most promising area of research in advanced digital circuits. Except for material physics, of course.

      Probably...

    56. Re:Bank balance by Anonymous Coward · · Score: 0

      Re-Read "When the Machine Stops"...

      This is a replay of the INTEL decision to decide who needs accurate CPUs and who doesn't.

      In Zimbawe where they are into billions maybe they don't care. In the US cents in my checkbook are important,

      Either way cheapening is not something to work towards.

    57. Re:Bank balance by mikael · · Score: 1

      There was argument about this in the game industry back in the late 1990's. Some people refused to believe that games would ever need 24-bit quality for images, and that 8-bit colormap images would remain in use forever.

      --
      Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
    58. Re:Bank balance by ZombieWomble · · Score: 3, Insightful
      I don't think any of these things particularly benefit from this type of processor. All of the situations you describe involve some degree of randomness, but this CPU doesn't sound like a source of useful random values at all.

      The randomness in these processes occurs in particular places, in particular quantities - this processor presumably produces some characteristic amount of randomness in each calculation, but the odds on it being a meaningful amount for whatever arbitrary calculation you're doing is vanishingly small - and given it's apparently treated to give different amounts of randomness in different bits, it's almost certainly non-uniform as well.

      In almost all simulations you want to make use of extremely well-controlled random numbers - something which adding some noise as part of your floating-point calculations is not.

    59. Re:Bank balance by Anonymous Coward · · Score: 0

      What bloody MP3 player do you have?

    60. Re:Bank balance by StormReaver · · Score: 1

      > Connoisseurs may claim to be able to taste the difference between [well water] and tap water, but that's just the extra tang from all the bull shit.

      This is off topic, but interesting nonetheless. I lived in the country for twelve years, and drank mostly well water for that era. Rest assured that after living on well water for years, tap water tastes like it came from a heavily trafficked swimming pool, and is as obvious as a kick in the head. The heavy stench of chlorine in even good tap water is abusive to taste buds that haven't become acclimated to it. Even now, three years later, I still use a commercial filter on my tap to make the water taste almost as good as that from the country well.

      Incidentally, I never noticed how bad tap water is until I moved out into the country. It took a little while for me to realize why the well water tasted so...odd. It's because that was the first time I'd tasted unpolluted water. Up until that point, I had always lived in various suburbs that had city-managed water, and cities always pollute the water with chemicals in order to kill toxins. It may be necessary, but it tastes bad. Since I had grown up with it, I didn't notice it until I'd had untainted water for a few years.

      As an aside, for those who don't know, a country well isn't usually a deep hole in the ground with water at the bottom. It's usually a long pipe dug into the ground that taps into an large underground river or water table.

    61. Re:Bank balance by wisty · · Score: 2, Insightful

      Accuracy might not matter for some steps in an implicit, iterative numerical scheme.

    62. Re:Bank balance by quarterbuck · · Score: 1

      Offtopic, but it is not very difficult to taste the difference between well water and tap water. Well water tastes slightly muddy. The actual mud in the region and trees/plants around the well change the taste too. Easy way to approximate the taste of well water is to throw in a couple of pieces of mud bricks into the container of water or to store water in a earthen pot.
      That said, I can't tell the difference between Evian and tap water.

      --
      http://slashdot.org/submission/1062723/Cheap-mobile-data-plan?art_pos=2
    63. Re:Bank balance by quarterbuck · · Score: 1

      There are countless applications for a computer that don't depend on accuracy, but do depend on speed. For example: gaming, stock analysis
      Do you work for Lehman brothers by any chance ?

      --
      http://slashdot.org/submission/1062723/Cheap-mobile-data-plan?art_pos=2
    64. Re:Bank balance by Firethorn · · Score: 2, Insightful

      In all probability this would never make it into usage as a CPU, more likely a dedicated section of silicon performing the function of a GPU/FPU/DSP. Actual control instructions would be high-integrity, just the low significance digits would get the 'cheap but a bit more unreliable' methods.

      I'd like to see how much an image would change if you imposed a 1% chance of a 10% error in either the chroma or luminance of each pixel. I'm willing to bet it'd be 'take a magnifying glass and the images next to each other to tell'. Change it to 30-60 hz video, and the perception of differences would go away.

      --
      I don't read AC A human right
    65. Re:Bank balance by Anonymous Coward · · Score: 0

      x86 processors already do this. If you want accuracy use the 80-bit floating point instructions. If you want speed use the SIMD instructions to process multiple 32-bit values in parallel. And the trade-offs are well understood.

      I would guess that a probabalistic processor would most be most useful for the kinds of problems where the answers are slow to calculate but quick to check (e.g. factorizing prime numbers).

    66. Re:Bank balance by Anonymous Coward · · Score: 0

      All I can respond with is "no shit Shirlock". Sometimes you don't need 32 or 64 bits of accuracy and 16 will do. The point of this is you can sacrifice bits for speed and get large speed ups. If they make this selectable then it would be a huge improvement in some applications. No one is claiming that it's a panacea, and there is no use in stating the obvious that Accuracy and speed are important in applications; I'm pretty sure 99% of the people on slashdot are well aware of that.

    67. Re:Bank balance by Hognoxious · · Score: 1

      I am claiming that the cent is not the smallest unit of currency produced by the US.

      You and I can trade in picodollars and do the accounting between us in the same, but good luck enacting those transactions through any banking or clearing system.

      the US did produce physical currency smaller than a cent.

      did != does.

      --
      Confucius say, "Find worm in apple - bad. Find half a worm - worse."
    68. Re:Bank balance by Anonymous Coward · · Score: 0

      [QUOTE]With regards to music, they're not talking about skips and pops, they're talking about extremely slight modulations in pitch or, in the case of video, a very slight difference in color.[/QUOTE]
                Except they aren't. They THINK they are, but that's not how MPEG decoding works. A single-bit error can have a large change in output.

                And once you get to the complexity of having these "low-accuracy" cores, you might as well just have DSPs.. they can run specialized use MUCH faster than a general-purpose CPU and tend to be low-power.

    69. Re:Bank balance by memco · · Score: 1

      Will the controller rely on the accuracy or efficiency? I don't want my finances calculated rightly 99.9% (or in the case of this chip 99%) of the time.

      --
      Get me a meat pie floater!
    70. Re:Bank balance by jsiren · · Score: 1

      Where I live cash transactions are rounded off to the nearest 5 cents. As someone mentioned, Finland didn't even bother with the 1 and 2 cent coins. Before the Euro conversion we had long ago withdrawn our 0.01 and 0.05 coins, and the 0.10 was rapidly becoming a nuisance. One could game the system by selecting payment methods between card and cash (the price is the same) according to the final digit. Then again, the maximum gain is 2 cents per transaction. At 500 potential transactions per year, with an average gain of one cent, one could expect to be a whopping 5 euros richer at the end of the year.

      A better get-rich-quick scheme is to keep one's eyes open and pick up any recyclable bottles and cans that people may have thrown away, worth 15 to 20 cents each.

      --
      Usage: km/h for speed (kilometers per hour); kph for very slow impulses (kilopond hours).
    71. Re:Bank balance by Nebu · · Score: 1

      I am claiming that the cent is not the smallest unit of currency produced by the US.

      You and I can trade in picodollars and do the accounting between us in the same, but good luck enacting those transactions through any banking or clearing system.

      Take in the full context of the thread, and you will see that I said you may very well trade in millidollars in the future, thanks to microtransactions. If I give some millidollars to Microsoft, Nintendo or Sony purchasing add-on content for for a game, doesn't that count as "enacting a transaction through a banking or clearing system"?

      the US did produce physical currency smaller than a cent.

      did != does.

      And again, I did not claim it "does" (nor for that matter do I claim that it doesn't). In the greater context of this thread, I am providing evidence for the point of view that perhaps rounding off our transactions at the "cent leve" is indeed arbitrary, given that we've rounded off our transactions at other levels in the past and it looks like we will round them off at yet other levels in the future.

      I don't know what else I can clarify to avoid strawmans here.

    72. Re:Bank balance by Pseudonym · · Score: 2, Insightful

      Think about a computation such as X - Y. If X and Y have the 3 first same digit, then you will have 0 significant bit for the result.

      Any numeric analyst worth their pay will have thought hard about every calculation. If there's a subtraction, then either it won't be two floating-point numbers of similar magnitude, or the result won't be crucial (e.g. it might be an error estimate rather than the actual result).

      If the characteristics of the hardware are known, then algorithms can be designed to suit them. This is just another tool in the toolbox.

      if you do anything more complicated than adding and multiplying, then you need accurate computation.

      Because, of course, IEEE-754 floating point numbers are renowned for their accuracy.

      --
      sub f{($f)=@_;print"$f(q{$f});";}f(q{sub f{($f)=@_;print"$f(q{$f});";}f});
    73. Re:Bank balance by Pseudonym · · Score: 1

      Quite. Any numerical method which is implicitly stable may well still work well enough on this hardware.

      --
      sub f{($f)=@_;print"$f(q{$f});";}f(q{sub f{($f)=@_;print"$f(q{$f});";}f});
    74. Re:Bank balance by commodore64_love · · Score: 1

      >>>I can't come up with a single lossless video codec besides "raw".

      Here's a few according to wikipedia. People have as little use for lossless video as they do lossless audio. I've heard of FLAC and Apple Lossless but so far have never found any Billboard Hot 100 music encoded using it. Anyway here's the lossless video formats:

              * Animation codec
              * CorePNG
              * FFV1
              * JPEG 2000
              * Huffyuv
              * Lagarith
              * MSU Lossless Video Codec
              * SheerVideo

      --
      "I disapprove of what you say, but I will defend to the death your right to say it." - historian Evelyn Beatrice Hall
    75. Re:Bank balance by Anonymous Coward · · Score: 0

      It would be much better if only programmers had to deal with the issue. I imagine the accuracy level would have to be essentially hardwired into the chip, that is, a probabilistic chip would be fundamentally different than a deterministic one. What I hope though, is that some way could be found to switch the processor between probabilistic and deterministic depending on what has to be done. The burden would then fall to the programmers, who are much better equipped to decide how accurate their calculations need to be.

      Worst case scenario though, everybody just buys deterministic processors by default, and the probabilistic processor becomes an optional performance enhancer like a GPU.

    76. Re:Bank balance by Anonymous Coward · · Score: 0

      Maybe I just am not understanding things, but I believe any inaccuracy in any program would be a bad thing.

      Programs usually require accurate calculations to run properly. If you check a error code, and its inaccurate, your program could think a error occured when in fact no error accured. If you do pointer arithmetic and its inaccurate, your program could crash with a segfault or corrupt itself.

      Sure, some calculations could be inaccurate, such as batch operations on big pieces of data. But any inaccuracy in anything the program requires to run, and the program could be in deep shit.

      If computers used analog signals, such a thing could be useful in video and audio, but computers dont, they use digital signals. Any inaccuracy in a digital signal could corrupt the whole thing, or at the very least, make a second or so unplayable (and I have seen some players that are unable to play past a error, even if you wait for the error to pass, the rest is unviewable unless you tell it to stop and start playing at a location past the error).

      Personally, I think this chip will only be useful outside of the CPU, if at all.

    77. Re:Bank balance by arminw · · Score: 2, Insightful

      ... In the US cents in my checkbook are important....

      Would that not depend on whether the errors made were equally in your favor and against it? If you did a large number of transactions and half of them added a penny or two to your account and half of them subtracted a similar amount, it would all even out in the, would it not? Only if the errors were unidirectional, would there be a problem in the long term.

      --
      All theory is gray
    78. Re:Bank balance by ozphx · · Score: 2, Insightful

      You wha?

      I think hardware and software designers already have that covered when they perform processing on different parts of your system, such as your CPU, or GPU...

      Specialization is a good thing, unless you have a preference for the performance of the directx reference rasterizer....

      --
      3laws: No freebies, no backsies, GTFO.
    79. Re:Bank balance by Bazar · · Score: 1

      You think gaming can be done without paying attention to accuracy?

      You jump up a ledge, your computed land zone is 0.5 units below the ledge itself. You fall through the world and die

      Texture wise you'd see all kind of errors, which given how graphics have evolved to look more realistic, seeing doors hang mid-air would be going a few steps back.

      Finally bugs. When you encounter a bug that caused the game to crash, you'll never be sure what caused it.

      As for scientific research, the Intel pentium had a bug that could cause a division to return inaccurate results. The result, Intel processors were shunned for research purposes.

      Nearly all of the operations done on a computer/console are used in future calculations, and require 100% accuracy. This chip will be of no use at all.

      What this chip could be useful in, is primitive applications that don't have anything like an operating system and perfect accuracy isn't required.

      I can see a lot of mechanical applications, pretty much anything that runs off AA batteries and thinks a little.
      Anything with lithium ion or a wall socket probably won't find a use from it

      --
      To avoid criticism; Say nothing, Do nothing, Be nothing.
    80. Re:Bank balance by FlyingBishop · · Score: 1

      I take it you've never drunk well water.

    81. Re:Bank balance by arminw · · Score: 1

      ...The politicians have slowly but surely devalued our money to 1/45th its value in 1933...

      That's because what what we call "money" is now intrinsically worthless. For most of human history, the medium of exchange, what we call money had some intrinsic value, because it could not arbitrarily be created without work and effort. In our modern era, whoever has the ability to create money and not go to prison will never go broke. This means that whatever entity does this, reduces the value of whatever money is worth. The stuff we call money is not immune to the laws of supply and demand. The more of a commodity that exists, the less a given unit will be worth. The amount of gold takes to buy a loaf of bread or pay for a night's lodging in an average hotel has not really changed all that much over time.

      --
      All theory is gray
    82. Re:Bank balance by Profane+MuthaFucka · · Score: 2, Interesting

      I don't think I agree. This processor could bring more lifelike movies to my house, for less money. I'm guessing that with this chip popping and rattling, I could get rid of the guy I hired to cough loudy and fumble with crinkly bags of chips in my "true movie experience" home theater room.

      --
      Fascism trolls keeping me up every night. When I starts a preachin', he HITS ME WITH HIS REICH!
    83. Re:Bank balance by Hal_Porter · · Score: 1

      You missed an opportunity there.

      You realise that for once "FRIST PS0T!!11" would have been ontopic, Funny and Insightful.

      --
      echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;
    84. Re:Bank balance by Hal_Porter · · Score: 1

      What about error correction?

      NAND flash chips are dense enough that they have errors, it's up to the user to error correct those errors away.

      I think there's some merit in scaling things to the point where they become unreliable and then using error correction to fix the unreliability.

      --
      echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;
    85. Re:Bank balance by nsheppar · · Score: 1

      Having drunk well water many times, I can tell you with certainty that I can taste the difference between well water and non-well water.

      --
      Correctness matters. Mercy matters more.
    86. Re:Bank balance by Hal_Porter · · Score: 1

      24 bits of colour data, i.e eight bits for Red, eight bits for Green and eight bits for Blue for images is probably quite close to the limit of what your eyes can actually see. Just like 16 bits of audio is probably quite close to the perceptionlimit for audio. Audiophiles may disagree on the last bit, but then they disagree with the Nyqvist theorem and double blind tests too.

      Mind you during processing there might be an argument for processing at a higher bit depth and then downconverting. E.g. you could process audio at 32 bits, make sure the errors stay in the bottom 16 bits and then when you downconvert they will disappear.

      Finally 32 bits of colour data might be faster due to alignment issues. Still it's worth pointing out that 32 bit pixel formats often use 8 bits for alpha level, i.e. only for mixing images together. Probably most video is processed at more than 8 bits per component too, it's only the final output which is 8 bit. With video there are good dithering algorithms too like Floyd Steinberg. They preserve some of the information when you down convert.

      --
      echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;
    87. Re:Bank balance by yndrd1984 · · Score: 1

      If you did a large number of transactions and half of them added a penny or two to your account and half of them subtracted a similar amount, it would all even out in the, would it not?

      Until you get hit with a a $40 overdraft charge for being a penny short ...

    88. Re:Bank balance by arminw · · Score: 1

      ...Until you get hit with a a $40 overdraft charge for being a penny short ...

      I suppose that would apply only to people who keep their account on the ragged edge of empty. I always try to keep at least $100 cushion in case my arithmetic is a little off.

      --
      All theory is gray
    89. Re:Bank balance by phoenix321 · · Score: 1

      If you're a programmer: enjoy the speed boost if needed or program for the accurate-only CPU when lazy.

      If you're a program user: you will not notice anything except raw speed, just like with dual or quad core systems now.

    90. Re:Bank balance by phoenix321 · · Score: 1

      Well, you're still calculating your significant digits with full precision. This is about many "significant" digits that only need to be precise in more than 99% of the calculations.

      Choosing a smaller datatype is going to be less precise in 100% of the cases, inaccurate computing with a larger datatype is going to be less precise in 0.1% of the cases - AND faster. See the point?

    91. Re:Bank balance by mollymoo · · Score: 1

      Detecting and correcting single bit errors isn't too computationally expensive and you can do it easily in hardware, but to detect and correct multi-bit errors you need a lot more horsepower.

      --
      Chernobyl 'not a wildlife haven' - BBC News
    92. Re:Bank balance by Anonymous Coward · · Score: 0

      There are countless applications for a computer that don't depend on accuracy, but do depend on speed. For example: gaming, stock analysis, scientific/mathematical research etc.

      Wow! Scientific and mathematical research usually needs both speed and accuracy? "How many significant digits do you have?" --this is what my boss often asks me. And it is hard to believe that you can carry out e.g. computational fluid dynamics with for instance single precision.

    93. Re:Bank balance by durrr · · Score: 2, Insightful

      Inaccurate = my darts miss the target by up to a meter.
      Random = my darts may be assigned any possible movement vector with equal probability.

      Please understand that there's a difference between these two. If i'm inaccurate we can compensate by altering the mechanics of our 'game'(make a huge dartboard, triangulate from multiple throws). Whereas if i'm random we can't really do much to help.

      Accuracy(or lack of it) is not very challenging to measure either, and once you have it measured it should be trivial to compensate until the rate of significant errors drop lower than the chance of you being hit by lightning or whatever is considered within safe bounds.

      You should consider that you could spend 85% of your cpu cycles on error corrections to achive equality with precision circuits while keeping the advantage of having 1/30 power cost. The advantage of 1/30 the powercost doesn't only(or neccesarily) translate to smaller utility bills. It also means less heat, which doesn't only mean less nosiy fans but also bigger, more powerful chips(with noisy fans). Scale your current cpu with 10x the amount of transistors at current tech and your computer will rival your microwave in heating power. At 1/30th the power that would still only be 1/3 of what you're already using.

      Saying this technology will have no use at all is a bit unimaginative, unless you perhaps have a lot of stocks in the current industry?

    94. Re:Bank balance by Hal_Porter · · Score: 1

      You don't need to correct multibit errors.

      You could detect and correct single bit errors, and detect multi bit errors and replace the cell with one of the ones in the spare pool. Which is how NAND ecc works.

      --
      echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;
    95. Re:Bank balance by sakari · · Score: 1

      It's safe to say that YOU can not hear the difference, but that doesn't mean I can't notice the differences between lossless audio and MP3 even at 256 kpbs.

      And I certainly can tell the difference between well water and tap water, even here in Finland where tap water is high quality and is the main source of drinking water.

    96. Re:Bank balance by N1AK · · Score: 1

      Also chaos theory applies, which can amplify some errors over time as the values propagate. This greatly complicates the problems in real world examples.

      If the article is correct that this change can lead to a 21,000% increase in computer speed / power consumption then don't consider what we can already do perfectly well with the resources we have, instead consider what we would like to do with a with resources well outside current limitations and decide what level of accuracy is acceptable.

      I imagine many stock traders would be perfectly happy to introduce limited error if it allowed them to process information in a way they are currently unable to do. If the issue of aggregated errors is important it may be possible to regularly run the data through a error free system to counter this (although this would depend on many things).

    97. Re:Bank balance by Bangz · · Score: 1

      Game logic and physics are both required to be deterministic, I think random error in these systems would be bad. Some parts of rendering need to be error free, such as the vertex shaders (you don't want your triangles wobbling all over the place), but their accuracy becomes less important with distance (although z fighting may be an issue), whereby a lower level of detail on calculations at the cost of speed is currently done in algorithms already. Graphical rendering and physical simulation of choatic systems, such as weather (wind, rain, snow, heat haze), water, and systems whereby choas wouldn't be so noticeable like reflection maps would not have a detrimental effect on visual quality. I can't see some parts of an AI system not being hurt to badly by this error either.

    98. Re:Bank balance by godrik · · Score: 1

      My point was not that floating point are better or worse. My point is that 3 digit accuracy on the result IS NOT 3 digit accuracy in the computation.

      This effect is known and dealt with in processor by having FPU registers bigger than CPU registers so that internal computation got more accuracy

      Moreover, when you do some image filtering, you do not know in advance whether you are going to completely get rid of a color component or not. It is thus difficult to estimate how much precision you need. This is the point of choosing float or doubles. You suppose that a xx-bit floating point number would be enough for your computations.

      Lowering the accuracy of floating point computation to get more power is not new. The cell processor used to do that...

      So this technology could be useful if you could tune your precision requirement. But I do not believe that you could really tune it efficiently from the hardware.

    99. Re:Bank balance by Anonymous Coward · · Score: 0

      A skip or a click in audio and video is not caused by small variation in sample values, but relatively huge portions of missing or damaged data. Our ears could tolerate a lot of noise before we picked it up conciously. For proof of this, look at all the people wearing crappy headphones.

    100. Re:Bank balance by Kelbear · · Score: 1

      It would require careful consideration of where the "fuzziness" can be accepted. Obviously things that are critically significant can't be fudged, like player control in a game, or immediate surroundings. But even in today's games, LOD (level of detail) is applied so that that scenery nearby is shown at full detail, while distant scenery only displays the bare essentials and improves in quality as you approach. How the player tosses a rock is critical because it's closely monitered by the user, he presumably is throwing it for a reason, and expecting a specific result. But how a landslide tumbles can be fudged since you're only looking at the general landslide, rather than looking for a pebble to fall with pinpoint accuracy after bouncing down a mountain.

      But this is just an example, I really don't think this will pop up in games because the extra work involved probably won't be justified by the gain in speed, and the market probably won't feel compelled to include this new chip into their computers (Ageia PhysX for example).

    101. Re:Bank balance by mollymoo · · Score: 1

      SLC NAND works like that, but MLC NAND (or rather the controller) does have to detect and correct multi-bit errors. There are 2 (or more) bits per cell so errors tend to affect more than one bit. Read errors are frequent enough that failing to retrieve data on single-cell errors isn't generally considered acceptable.

      --
      Chernobyl 'not a wildlife haven' - BBC News
    102. Re:Bank balance by Hal_Porter · · Score: 1

      Hmm, I didn't know MLC used a stronger ECC. It seems you're right

      http://www.spansion.com/application_notes/Types_of_ECC_Used_on_Flash_AN_01_e.pdf

      But actually look what's happening here. The generations of flash I've used have gone like this

      NOR. No ECC. Low density
      SLC NAND. Hamming code ECC. Higher density (2xNOR).
      MLC NAND. BCH or Reed Solomon. BCH seems to be the most common. Highest density (2xSLC)

      It seems like the trend is to have less reliability in built reliability in return for smaller cells and add smarter error correction in the controller. Which was my point - you can live with any bit error rate that you can correct.

      I bet the cost of silicon for the controller is negligable compared to the NAND array anyway.

      --
      echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;
    103. Re:Bank balance by nasch · · Score: 1

      I'm not sure exactly, but it sounds like you're referring to the gold standard? US currency has been fiat for quite a long time now and is thus unrelated to gold. Or perhaps you're referring to a totally unrelated meaning of the term "dollar", in which case I'm not sure why you mentioned that "The politicians have slowly but surely devalued our money".

    104. Re:Bank balance by mollymoo · · Score: 1

      The cost of error correcting logic is low compared to acres of silicon for storing data, but not so low compared to the silicon used in, say, an ALU.

      --
      Chernobyl 'not a wildlife haven' - BBC News
    105. Re:Bank balance by CAIMLAS · · Score: 1

      I can't speak for anyone else, but I can certainly taste (and smell) the difference in tap vs. well vs. bottled - and so on and so forth. I can taste the plastic leech in bottled water (even if it's been presented to me in a glass); it's not a psychosomatic thing, as I can tell the difference, blind. I can taste the fluoride, as well, for what it's worth. Just because you can't tell the difference doesn't mean others can't.

      I also have an obscenely keen sense of smell (and it was worse back when I didn't smoke), so that might have something to do with it. But there are certainly others like myself in this regard.

      Audio, on the other hand, isn't something I can tell the difference in - at least when we're comparing lossless recordings with 192kbps MP3s. Depending on the encoder, 128kbps is evidently encoded/tinny to me with half-decent headphones. But then, I don't have the best hearing in the world - I'm slightly deaf in my left ear from an explosion. So to each their own.

      --
      ~/ssh slashdot.org ssh: connect to host slashdot.org port 22: too many beers
    106. Re:Bank balance by CAIMLAS · · Score: 1

      I suspect that Google and other slightly-less-than-completely-deterministic tasks could utilize this technology. It might also have applications in AI.

      Other than that, I don't think it has much use. How much error/randomness is a person going to take in a computer? We've spent decades trying to get OSes that are stable and glitch-free. Now we're going to introduce them into our CPUs?

      --
      ~/ssh slashdot.org ssh: connect to host slashdot.org port 22: too many beers
    107. Re:Bank balance by ivan256 · · Score: 1

      BadAnalogyGuy.

      You have been trolled.

    108. Re:Bank balance by Anonymous Coward · · Score: 0

      And $81,000.31 is a much more correct answer!

      Exactly! (pun intended)

      So basically what he is saying, is to shift the burden of mathematical correctness from the hardware... to the software?

      I highly doubt that any gains in speed chip-wise will translate into final product gains once the extra overheard of checking/compensating is implemented in software.

      While I understand his point, it's cheaper in the long run to make ONE accurate chip & use for all devices, than to make a custom 1/2-assed chip for cheap applications. ie. any cost savings would be erased due to increased manufacturing costs/facilities.

      I guess he used such a chip to do his cost/analysis computations.

    109. Re:Bank balance by Anonymous Coward · · Score: 0

      24 bits of colour data, i.e eight bits for Red, eight bits for Green and eight bits for Blue for images is probably quite close to the limit of what your eyes can actually see. Just like 16 bits of audio is probably quite close to the perceptionlimit for audio.

      24 bits actually isn't enough for color.

      Just for example: for any given color, 8 bits of intensity variation is barely enough to make a gradient from black to full intensity smooth enough that your eye doesn't see discrete steps. However, the problem is that 24 bit RGB only gives you 8 bits of intensity variation for pure red, pure green, and pure blue. When you start forming other colors by combining them, you lose the ability to have 255 steps of intensity, and cannot make a smooth gradient any more.

      To see why, consider 2 bits per channel. At 2 bpc you get 4 levels, so possible intensity levels for a primary color are black, 33%, 66%, 100%. Say you want to make a color which is 33% R, 66% G, and 100% B. Can you figure out how to vary the intensity of that color without altering the ratio of R:G:B?

      This problem is less severe at 8 bits per channel, but still not completely solved. For this reason, professionals often do work with more than 8bpc. Photoshop has supported 16bpc for years and years, and you can get I/O hardware (scanners, graphics cards, monitors, printers) which supports >8bpc (often at least 10 bits).

      There are other color spaces which work better for this sort of thing, such as HSV, but they're not necessarily what display devices actually implement.

    110. Re:Bank balance by clone53421 · · Score: 1

      Yeah. You'd almost think he TRIED to come up with terrible analogies or something.

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
    111. Re:Bank balance by clone53421 · · Score: 1

      You mean, it's... like... a BadAnalogy?

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
    112. Re:Bank balance by clone53421 · · Score: 1

      That said, the US did produce physical currency smaller than a cent.

      AFAIK, mills were issued by states (and some private entities), not by the U.S. government. (Unfortunately the Wiki doesn't directly confirm that they were not issued by the U.S. government, it just says that states and private entities did produce them...)

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
    113. Re:Bank balance by Anonymous Coward · · Score: 0

      That's because what what we call "money" is now intrinsically worthless. For most of human history, the medium of exchange, what we call money had some intrinsic value, because it could not arbitrarily be created without work and effort. In our modern era, whoever has the ability to create money and not go to prison will never go broke.

      Hey buddy: how about you study real history and find out what happens when societies try to tie their economies to the value of a scarce metal, ok? It's not all roses.

      Economic growth is generally held to be a good thing, for reasons which I hope are obvious. How do you grow an economy whose money supply is restricted to the supply of gold? especially if you do not actually control the supply of gold? One of two things ends up happening.

      The popular option, historically, was for governments to 'debase' currency by reducing the amount of precious metal struck into each coin. This of course is despised by people of your ilk.

      Another is to stick to your purist 'mah money haz to be worth the same, always!' mentality, which actually results in the price of money going up: that is, people begin to be willing to exchange more goods for the same amount of money today than they were yesterday, because money is getting more scarce as the population grows or standards of living go up. This is deflation, the opposite of inflation, and while it might sound like a great idea to you if you have money, it actually turns out to be a horrible thing for society and even for you personally in the long haul since it tends to stunt further economic growth.

      There is a rich history of problems brought about by 'hard currency' in the U.S. if you care to look for the real story and try to actually understand it rather than seeking to rant about how far we've fallen from the One True Ideal of Gold. There are valid and good reasons why we finally went off the gold standard. We tried to make it work for a very long time. It doesn't work. Deal with it.

      The stuff we call money is not immune to the laws of supply and demand. The more of a commodity that exists, the less a given unit will be worth.

      Gold is immune to the laws of supply and demand how??

      Anything you use for money will have its real value change over time. The laws of supply and demand dictate this! The whole notion that if only you tied your currency to gold, everything would be better because prices would be stable is the worst kind of ridiculous magical thinking. Gold is just metal. It looks pretty so it's used in jewelry, and it has some nice chemical properties which make it valuable for certain industries (such as corrosion-resistant platings for electrical connectors). Why should this one particular commodity be the basis for our whole economy, especially when there's so little of it to go around?

      Far better to have responsibly managed fiat money. Are abuses possible? Yes. But historically the gold standard led to plenty of badness itself, paradoxically even more so when it was rigidly adhered to. Responsible governance is a necessity no matter what currency system you use. There is no magic bullet.

    114. Re:Bank balance by bluefoxlucid · · Score: 1

      "Like a GPU" is funny, because consumer graphics cards are inaccurate while $15000 high-end cards are accurate.

    115. Re:Bank balance by bluefoxlucid · · Score: 1

      Nyqvist theorem has lots of problems. For example, representing an audio stream containing 22kHz and below frequencies in 44kHz sampling could fail to properly represent cases where compound signals with components at or near the same frequency overlap closely together, which generates destructive feedback and harmonics outside the sampling frequency, and thus is represented as a set of lower frequencies. When reconstructing, you're looking at lower frequency signals with harmonics around the original frequencies, rather than being able to reconstruct the original real signal.

    116. Re:Bank balance by clone53421 · · Score: 1

      However, the problem is that 24 bit RGB only gives you 8 bits of intensity variation for pure red, pure green, and pure blue. When you start forming other colors by combining them, you lose the ability to have 255 steps of intensity, and cannot make a smooth gradient any more.

      Fact is, changing R, G, or B by 1/256th of its range is nearly imperceptible. I challenge you to find any two RGB colours, whose RGB values are individually different by no more than 1, which look perceptibly different when placed side-by-side.

      To see why, consider 2 bits per channel. At 2 bpc you get 4 levels, so possible intensity levels for a primary color are black, 33%, 66%, 100%. Say you want to make a color which is 33% R, 66% G, and 100% B. Can you figure out how to vary the intensity of that color without altering the ratio of R:G:B?

      You can't, but that's an artificial scenario: 33,66,100 is quite noticeably different from the next step down (33,66,66, we'll call it). With 8 bits per channel, the next step down is a slightly different hue, but this isn't noticeable. (If that argument held, you'd similarly have to argue that 48-bit colour isn't good enough because you can't diminish 7fe2,83c9,03a5 by 1/65536th of full-intensity without changing its hue.)

      To illustrate, say you have a 24-bit colour, 80,84,04, and you want to reduce it by 1 – so you come up with 7f,83,04. Yes, you've changed the ratio of R:G:B, but the human eye can't tell that it's a different hue. However, bump either of those three values up or down by one and you still can't tell the difference anyway.

      The only time 16 bits per channel is needed is during the intermediate stages, where the down-sampling would result in loss of details which are later amplified – for example, increasing the gamma to brighten a dark image. You still only really need 8 bits per channel to display the final result: anything more than that won't give any noticeable improvement to the human eye.

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
    117. Re:Bank balance by clone53421 · · Score: 1

      Um, not all tap water tastes like free chlorine.

      http://en.wikipedia.org/wiki/Chloramine#Uses_in_water_treatment

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
    118. Re:Bank balance by clone53421 · · Score: 1

      I can taste the fluoride, as well

      I doubt that very much. I don't doubt that you taste something, but I doubt that it's fluoride.

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
    119. Re:Bank balance by clone53421 · · Score: 1

      Except they aren't. They THINK they are, but that's not how MPEG decoding works. A single-bit error can have a large change in output.

      Actually, it depends on where the error is introduced. If it's near the output, the difference might be slight, and I don't think anyone is suggesting it'd be a good idea to introduce errors near the input or in portions of the algorithm where they'll end up being amplified into something noticeable. The whole entire point of "sacrificing accuracy for speed" is that the loss of accuracy isn't noticeable.

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
    120. Re:Bank balance by againjj · · Score: 1

      Or avoid a charge being a penny over ...

    121. Re:Bank balance by Anonymous Coward · · Score: 0

      unless that is your bill silly

    122. Re:Bank balance by Hal_Porter · · Score: 1

      Yeehaw. I done trolled the lake and caught me an audiophile.

      All Nyqvist's theorem says is the if you sample a frequency F, any frequencies upto F/2 will be preserved. You make F big enough so that F/2 is outside the range of frequencies people can hear and you're good to go.

      I dunno about you, but I'm pretty sure I don't want my hi fi emitting frequencies above 22-24khz which is N/2 for CDs and computer generated sounds.

      I can't hear them - actually if you go here
      http://www.jimmyr.com/blog/hearingloss.html ... you'll find you can't hear them either.

      Having spent some time in the same room as an ultrasonic PCB cleaner, I know I don't want to be around ultrasound.

      --
      echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;
    123. Re:Bank balance by karit · · Score: 1

      Also remember this chip is running seven times faster than current chips. Maybe run every calculation until get two or three the same or maybe a win by two scenario and pick that as the correct answer, so long as on average you will get two agreeing ones in less that seven iterations you are still running faster with less watts to do the calculation.

      --
      http://blog.karit.geek.nz/
    124. Re:Bank balance by iamacat · · Score: 1

      I bet you will sing a different tune when you can get 26 hours of charge from your video player in exchange for a bad pixel every minute or so. And, while I don't see banks suffering from expensive/power inefficient CPUs quite as much as from subprime mortgages, I think an extra cent deposited to your account every month would compensate you for any rounding errors quite nicely if they did need to save money in that area.

    125. Re:Bank balance by iamacat · · Score: 1

      High accuracy is required for encoding music and video, though.

      Oh really? You would wait 7 hours to compress your vacation movie from HD camcorder into a torrent to share with friends when you can do that in one hour with a bad pixel every minute or so? I would say every application which needs more CPU power than current technology can provide operates on huge amounts of input and output data and as such can live with a few isolated errors.

    126. Re:Bank balance by bluefoxlucid · · Score: 1

      All Nyqvist's theorem says is the if you sample a frequency F, any frequencies upto F/2 will be preserved.

      "If a function x(t) contains no frequencies higher than B cps, it is completely determined by giving its ordinates at a series of points spaced 1/(2B) seconds apart."

      In other words, it states that you can completely and accurately reconstruct the signal from so many samples. The poor assumption is that a signal synthesized by the organic combination of some set S of frequencies is going to contain only frequencies between 0 and max(S).

      There is also a technicality-- but not one a human can notice, of course-- that Nyqvist's theorem assumes a steady, continuous signal with its first and last samples marking the exact beginning and end of the signal. In a dynamic signal, I can introduce a new frequency at a point 1/88200 seconds after (and before) a sample is taken, which will be difficult to reconstruct precisely if accompanied by several other frequencies. The corner cases of extremely complex waveforms-- for example, a saxophone-- that are essentially controlled by higher-frequency fluctuations that to the crude observer affect overall amplitude at a lower frequency also have some audible drift, but not noticeable by an untrained ear. Live saxophones sound far more crisp than well-recorded saxophones ;)

      It's not something you'd notice in easy listening. In many simple cases it's not something you'd notice without lots of concentration. In some specific cases there is no difference. In many real-world situations, however, a side-by-side comparison will expose things that aren't readily apparent to casual listeners.

      In practice, neither of the two statements of the sampling theorem described above can be completely satisfied, and neither can the reconstruction formula be precisely implemented. The reconstruction process that involves scaled and delayed sinc functions can be described as ideal. It cannot be realized in practice since it implies that each sample contributes to the reconstructed signal at almost all time points, requiring summing an infinite number of terms. Instead, some type of approximation of the sinc functions, finite in length, has to be used. The error that corresponds to the sinc-function approximation is referred to as interpolation error.

    127. Re:Bank balance by Hal_Porter · · Score: 1

      The poor assumption is that a signal synthesized by the organic combination of some set S of frequencies is going to contain only frequencies between 0 and max(S).

      That's not a poor assumption - there is an antialiasing filter that cuts off sharply before the Nyqvist frequency.

      The corner cases of extremely complex waveforms-- for example, a saxophone-- that are essentially controlled by higher-frequency fluctuations that to the crude observer affect overall amplitude at a lower frequency also have some audible drift, but not noticeable by an untrained ear. Live saxophones sound far more crisp than well-recorded saxophones

      Hey, I like live music much more than recorded music. But that's nothing to do with Nyqvist or signal to noise ratios or any technical detail. If I listen to live music I'm out boozing and carousing, and that is fun.

      --
      echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;
    128. Re:Bank balance by clone53421 · · Score: 1

      If the randomness introduced isn't "good" randomness, you might get the same (wrong) answer repeatedly if you rapidly calculate and recalculate the answer.

      Think of it as a random function that's seeded with the timer: a "bad" random function might give almost exactly the same value when the seed was 2982346 as it does when the seed is 2982347. Call it again in a second or two and you might get "good" pseudo-random values (e.g. they don't look similar).

      I know because I ran into this sort of problem when I "cleverly" called RANDOMIZE TIMER in every loop of a program because I thought it would give me "better" randomness. It didn't – just the opposite, in fact.

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
  2. Reminds me of... by rob1980 · · Score: 5, Funny

    Q: Why didn't Intel call the Pentium the 586?
    A: Because they added 486 and 100 on the first Pentium and got 585.999983605.

    1. Re:Reminds me of... by cbiltcliffe · · Score: 1

      I was thinking along the same lines.

      Although considering they call this thing a probabilistic chip, maybe we'll soon have the Infinite Improbability Drive.

      --
      "City hall" in German is "Rathaus" Kinda explains a few things......
    2. Re:Reminds me of... by FlyByPC · · Score: 1

      I was thinking along the same lines.

      Although considering they call this thing a probabilistic chip, maybe we'll soon have the Infinite Improbability Drive.

      We're going to need a really hot cup of tea...

      --
      Paleotechnologist and connoisseur of pretty shiny things.
    3. Re:Reminds me of... by machine321 · · Score: 5, Funny

      My computer's not slow, it's just being careful.

    4. Re:Reminds me of... by revery · · Score: 1

      +100 Whuffie for you

  3. 0.9999657:st post by assert(0) · · Score: 1

    innit?

    --
    (founded 95,000,000 yrs ago, very space opera)
  4. Accuracy with financial calculations. by onion2k · · Score: 5, Funny

    Accuracy with financial calculations is extremely important. Hasn't this guy ever watched Superman 3?

    1. Re:Accuracy with financial calculations. by Briareos · · Score: 2, Informative

      Hasn't this guy ever watched Superman 3?

      Maybe he just watched Office Space and missed the whole Superman 3 reference?

      np: Fennesz - Vacuum (Black Sea)

      --

      "I'm not anti-anything, I'm anti-everything, it fits better." - Sole

    2. Re:Accuracy with financial calculations. by Anonymous Coward · · Score: 0
    3. Re:Accuracy with financial calculations. by Firethorn · · Score: 1

      I'll note that he was making the point that the thousands part is far more important than the cents part.

      Basically, it sounds like he dumbed down the answer too much. Of course the cents are important in your bank account. And, more importantly, it's fairly trivial for us to KEEP that accuracy.

      Still, when you start expanding it to, say, a company's balance on the books, you tend to get errors. Think of it like a warehouse inventory - every time you do an inventory, there's a chance that somebody will count something wrong, and you'll come up with a slight error. Thing is, once that error is less than real 'noise' like shrinkage, defective products, waste, etc... It doesn't matter much and is easily compensated for. On another topic - voting ballots. You could have a 99.999% accuracy rate, but because you have millions of ballots, some will still be screwed up. In most elections, it doesn't matter, because the actual difference in votes exceeds the margin of error by a significant amount (.001% error rate, 6% difference in polling).

      Multimedia wise, if we can accept some error in the least significant bits for color or sound range, which we already do with lossy compression, in exchange for faster, cheaper, and cooler/more energy efficient chips, it could have great value.

      --
      I don't read AC A human right
    4. Re:Accuracy with financial calculations. by peragrin · · Score: 1

      quite correct the thousands is far more important than the cents, however 13,810.00 is really close to 13,000.81 right. it has all the same numbers in a similar order.

      Banks calculate out to the tens of thousands of a place simple because you need that much for rounding errors. heck in my business most items are priced out to the ten of thousands of place, getting pricing like $121.3456 for a cost.

      --
      i thought once I was found, but it was only a dream.
    5. Re:Accuracy with financial calculations. by Firethorn · · Score: 4, Informative

      quite correct the thousands is far more important than the cents, however 13,810.00 is really close to 13,000.81 right. it has all the same numbers in a similar order.

      Not by the fuzzy logic the guy's using. He's going for scientific accuracy. IE 13,000.81 (+-.001%). It's just our brains that compare symbols that would consider those numbers 'close'.

      In which case a $810 error in a $13k account is a big friggen error, and would violate the standards of the chip he's working on. Now, I don't know HOW he's making sure high order bits are done more accurately than the low order ones, but that's what the article mentions him doing.

      --
      I don't read AC A human right
  5. Use in MP3 Players by AmigaHeretic · · Score: 2, Funny

    So what you're saying is that it might make all my MP3s sound like they are AutoTuned? But the battery will last 30 times longer?

    I guess the question is can Cher sue over this technology?

    1. Re:Use in MP3 Players by phoenix321 · · Score: 4, Interesting

      If you bought a popular artist recently, your music is autotuned already.

      Anyway, this means that less than 0.1 percent of your decoded audio samples will be less 0.1 percent off. This is probably very acceptable outside concert halls and living rooms if it delivers large bonuses in battery saving or calculation speed.

      For example, we could use a much beefier compression algorithm than MP3 or current algorithms even longer on even smaller devices.

    2. Re:Use in MP3 Players by Anonymous Coward · · Score: 0

      Anyway, this means that less than 0.1 percent of your decoded audio samples will be less 0.1 percent off.

      How could it possibly be predicted how inaccurate it would be? Imprecision is one thing but "random errors" who knows.

    3. Re:Use in MP3 Players by phoenix321 · · Score: 1

      We predict it statistically, just with most other quality or process controll issues.

      Compare a series of computations of 300 inaccurate cores with the result of 10 deterministic ones. Observe the results, make sure that errors are evenly distributed, i.e. all inaccurate cores have a similar error ration and then you're set.

  6. Old Tech? by JorDan+Clock · · Score: 1

    Didn't Intel already implement this technology in their Pentium 2 FPUs? Didn't seem very desirable to me...

  7. wll, by greenguy · · Score: 5, Funny

    i scrfcd accrc 4 spd a lng tm ago

    --
    What if I do the same thing, and I do get different results?
    1. Re:wll, by hackstraw · · Score: 4, Interesting

      This whole thing is old and silly.

      Seymour Cray is known for saying "Do you want fast or accurate?" because back then there was no IEEE 754 spec (which is not infinitely precise) for floating point numbers at the time and machines were pretty primitive then and his machine did Newtonian approximations of many numeric calculations that were accurate to a point, just like John Carmack did (in software) with Doom's inverse square root.

      The moral of the story is that in 2009 and beyond its probably best to have hardware continue to be accurate. This is why we have digital 1s and 0s instead of some other base of computation.

      Now, in software, feel free to make things as sloppy as you want. If your bank (not mine) wants to round 13,000.83 to some other value, then by all means go for it. But I think that most of us are OK with accurate hardware.

    2. Re:wll, by Anonymous Coward · · Score: 0

      You also sacrificed a lot of vowels...

    3. Re:wll, by vux984 · · Score: 5, Funny

      i scrfcd accrc 4 spd a lng tm ago

      and it was going so well too... until you got thirsty and told your friend ..

      "hy! I wnt sm ck!"

    4. Re:wll, by osu-neko · · Score: 1

      The moral of the story is that in 2009 and beyond its probably best to have hardware continue to be accurate.

      Um, no. If we had to choose one or the other, you're right, that's the best choice. But only if first you make the extremely poor choice of insisting it has to be one way or the other rather than the actual best choice, which is, it's best to have hardware be offered in a variety of configurations. The best choice is to offer a choice.

      --
      "Convictions are more dangerous enemies of truth than lies."
    5. Re:wll, by Nebu · · Score: 1

      This whole thing is old and silly.

      [...]

      But I think that most of us are OK with accurate hardware.

      If there exist some people for whom probabilistic computers are useful, then I wouldn't call the research "silly".

      Seymour Cray is known for saying "Do you want fast or accurate?" because back then there was no IEEE 754 spec (which is not infinitely precise) for floating point numbers at the time and machines were pretty primitive then and his machine did Newtonian approximations of many numeric calculations that were accurate to a point, just like John Carmack did (in software) with Doom's inverse square root.

      Perhaps this "probabilistic square root" algorithm could be implemented as a single instruction in the probabilistic CPU, thus speeding this up for everyone.

      The moral of the story is that in 2009 and beyond its probably best to have hardware continue to be accurate.

      It's probably best, or deterministically best? Sorry, that was a bit of a "mean jab" there, but perhaps it's enough to give you an intuition that there are applications where "probably" is good enough (depending on what the exact probabilities are).

    6. Re:wll, by hackstraw · · Score: 1

      The moral of the story is that in 2009 and beyond its probably best to have hardware continue to be accurate.

      Um, no. If we had to choose one or the other, you're right, that's the best choice. But only if first you make the extremely poor choice of insisting it has to be one way or the other rather than the actual best choice, which is, it's best to have hardware be offered in a variety of configurations. The best choice is to offer a choice.

      Would you like Starter Accuracy (tm), Basic Home Accuracy (tm), Home Premium Accuracy (tm), Business Accuracy (tm), Or Ultimate Accuracy (tm). 31.983438350 bit or 63.677689235 bit versions of the aforementioned products?

      Sorry for the sarcasm, but I couldn't resist. I simply can't think of a market for this kind of processor. When I wrote about the Cray computer, odds are you have one of those in your pocket right now. Yes, cellphones are more powerful than the first couple of Cray supercomputers, and more accurate to boot.

      The markets I think of are laptops, servers, space, and supercomputing, where power is important, but none of them can sacrifice accuracy. I don't see this being much of a market for things like smaller portable devices like phones, PDAs or MP3 players because these devices already get up to 3-5 days of battery life, and if they get any smaller you will have to tattoo them on your skin, and then you have an infinite supply of power from body heat. Also, people don't go into the jungle where there isn't power that often. I'm within 5-10 feet of a power source pretty much 24hours every day.

      How would you develop code for such a device? You certainly couldn't test for correctness. Today, IEEE floating point is not 100% accuracy, but its consistent across machines, which is a good thing. Computing was a mess before the IEEE spec came about. If someone can think of the killer app for one of these, feel free to reply.

    7. Re:wll, by Anonymous Coward · · Score: 0

      Cray wasn't referring to circuitry of this type, he was talking about trade offs in standard logic design. Compare apples to apples for God's sake. Your comment about why we have ones and zeroes is completely wrong as well. We could do logic in any number of bases, however doing it in 0's and 1's greatly simplifies the hardware. Did you get your degree from a craigslist ad?

    8. Re:wll, by Anonymous Coward · · Score: 0

      I think the concept is tunable accuracy: for x86, the Pentium M introduced gating of unused portions of the chip. For media processing, what can shutting off the bits in registers (and throughout the ALU) for unnecessary precision give you? Or if it's cheaper to let them float than to zero them out, can you tolerate that noise?

      This could be less confusing to implement than it sounds, and still offer significant savings.

    9. Re:wll, by Anonymous Coward · · Score: 0

      "hy! I wnt sm ck!"

      does that mean you want some cock or cake? ;)

    10. Re:wll, by Anonymous Coward · · Score: 0

      Wasn't John Carmack who wrote it.
      I don't think anyone knows who wrote the original code, although we know that Gary Tarolli can take some credit.

      http://www.beyond3d.com/content/articles/8/
      Some old digging by Rys Sommefeldt

    11. Re:wll, by Anonymous Coward · · Score: 0

      I also want some cake.

    12. Re:wll, by mollymoo · · Score: 1

      The Cray and Doom approximations weren't probabilistic, they were just not as accurate as they could be. Given the same input they would always give the same output.

      Doom's inverse square root function gives me the horn - the way it manipulates the bits in a float to get the initial approximation is just beautiful.

      --
      Chernobyl 'not a wildlife haven' - BBC News
    13. Re:wll, by Aphoxema · · Score: 1

      What? I seem to have a problem with my probability networking setup. Sometimes my packets are mangled and go to the wrong places, and it takes a few dozen tries to log into Gmail, but it sure is fast!

      --
      "Most people, I think, don't even know what a rootkit is, so why should they care about it?"
    14. Re:wll, by Aphoxema · · Score: 1

      It doesn't have to be a primary processor. Much like graphics, sound, and supposedly physics processing outgrew the CPU, so could fast, wobbly processing.

      I know when I shoot a blinn shader with a ray I want a certain result, but it doesn't have to be a perfect result to be appealing... in fact... I can think of many times when an imperfect result is desirable.

      --
      "Most people, I think, don't even know what a rootkit is, so why should they care about it?"
  8. Top Ten Slogans by AmigaHeretic · · Score: 5, Funny

    TOP TEN SLOGANS FOR THIS NEW PROCESSOR:

    9.9999973251 - It's a FLAW, Dammit, not a Bug

    8.9999163362 - It's the new math

    7.9999414610 - Nearly 300 Correct Opcodes

    6.9999831538 - "You Don't Need to Know What's Inside" (tm)

    5.9999835137 - Redefining the PC -- and Mathematics As Well

    4.9999999021 - We Fixed It, Really

    3.9998245917 - Division Considered Harmful

    2.9991523619 - Why Do You Think They Call It *Floating* Point?

    1.9999103517 - We're Looking for a Few Good Flaws

    0.9999999998 - "The Errata Inside" (tm)

    1. Re:Top Ten Slogans by gbjbaanb · · Score: 4, Funny

      TOP TEN SLOGANS:

      runs Excel just as well as always :-)

    2. Re:Top Ten Slogans by getuid() · · Score: 1

      7.9999414610 - 300 Nearly Correct Opcodes

      Fixed.

    3. Re:Top Ten Slogans by drinkypoo · · Score: 1

      This would have been at least 9.23541235 times funnier if you had 10 slogans. Or you know, whoever wrote the list in the first place. Here's some other fdiv jokes, with these at the bottom.

      What I really wanted to say though (and decided to say it here due to your nick) is how did this get tagged 'amiga'? All I remember the Amiga sacrificing was resolution (in that it didn't have much color depth available for most purposes, "back in the day".)

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
    4. Re:Top Ten Slogans by AmigaHeretic · · Score: 1

      >>All I remember the Amiga sacrificing was resolution (in that it didn't have much color depth available for most purposes, "back in the day".)

      I don't know, but I remember that it was "good enough" for porn...you know, back in the day. ;-)

  9. It seems like when you need a precise calculation by rolfwind · · Score: 4, Insightful

    like financial things, you compare the end product with the end product of the same calculation run either through the chip again or another chip (or increasingly likely another core).

    Still would be faster too.

  10. DSP's? by Zantetsuken · · Score: 2, Insightful

    Isn't that the point of using a DSP? So you can use a slower CPU to run the firmware and the DSP do that grunt work of decoding, thus letting you save power with the low voltage CPU?

    My question is, if it's just as well to use a DSP, why not just use a damned DSP?

    1. Re:DSP's? by Anonymous Coward · · Score: 1, Insightful

      Presumably, the idea is to use this technology to make good-enough DSPs that are much more efficient.

    2. Re:DSP's? by Firethorn · · Score: 4, Insightful

      I think the point would be using a DSP/math coprocessor that uses 1/30th the power in exchange for a .001% loss in accuracy for non-essential tasks like music decoding.

      I mean, combined with the lousy earbuds most people use, who'd notice? Especially if it makes their MP3 player last 3 times as long as ones that use more traditional and technically accurate DSP/decoder?

      --
      I don't read AC A human right
    3. Re:DSP's? by Heather+D · · Score: 2, Informative

      Even with good earbuds this would probably not be noticeable. This will have a huge impact upon DSP systems if it pans out. It could have many other applications as well. Robotics, artificial intelligence, fuzzy logic, neural networks, just to name a few.

    4. Re:DSP's? by Fex303 · · Score: 1

      I mean, combined with the lousy earbuds most people use, who'd notice?

      No-one. But it would be fun to watch audiophiles with more money than sense claim that they could tell the difference.

    5. Re:DSP's? by Cassini2 · · Score: 1

      At least one hearing aid manufacturer deliberately does its DSP work in analog, to get the 1/30th the power with a minimal accuracy loss. The problem with digital filters (like DSPs) is that they use lots of power relative to analog filters. The fundamental design issue with what the author is suggesting, is that in digital the bits all have different weights. The difference between 2047+1=0 and 2047+1=2048 is huge, however in an ALU the difference is a single badly propagated carry bit.

      Analog electronics doesn't suffer from the bit weighting problem. Thus a little bit off in analog is almost always just a little bit off. It makes a big difference. A scratched LP that is still playable, and a scratched DVD, with a much better sound quality, is unplayable. I deliberately picked DVDs for this example, as CDs have an exotic error-correction algorithm which makes them playable even if they are fairly damaged. As such, it isn't fair to compare a scratched CD to either a DVD or an LP. CDs are by far the least scratch sensitive media, but LPs which are analog, are more usable with scratches than most other digital media.

      In any case, this is why some low power applications are implemented in analog and not digital.

    6. Re:DSP's? by electrosoccertux · · Score: 1

      Shh! You're going to aggro the audiophiles!

    7. Re:DSP's? by NeoSkandranon · · Score: 1

      Good. Trolling audiophiles is part of being a slashdot member.

      --
      If you can't see the value in jet powered ants you should turn in your nerd card. - Dunbal (464142)
  11. Financial accuracy is foremost by Anonymous Coward · · Score: 0

    Dearest depositor,

    Bank is using new probalistic computers, and might be having errors. Da, you will see you are having no money now. Please to be calling bank.

  12. Not completely correct by chthon · · Score: 3, Insightful

    If you read the chapter about the history about the IEEE FP standard in Microprocessors : a quantitative approach, then you will see that in the past accuracy was already sacrificed for speed in supercomputers.

    1. Re:Not completely correct by Anonymous Coward · · Score: 1, Interesting

      The IEEE FP standard defines a predictable specification. Whoever uses it can predictably understand the outcome of applying an FP operation to two operands. If there IS going to be inaccuracy in some least-significant digits of the resulting outcome, it is to be expected.

      However, in a probabilistic setting, certain outcomes may be right or wrong, on a case-by-case basis (possibly even affected by environmental factors such as temperature or noise). This is not an easy "spec" (if you can call it that) to work around with.

  13. Hmmm by Metabolife · · Score: 1

    What happens when you add up millions of these inaccurate accounts and end up gaining or losing millions of dollars?

    1. Re:Hmmm by BadAnalogyGuy · · Score: 5, Funny

      You get a one-way ticket to pound-me-in-the-ass prison.

      Watch out for your cornhole, bud.

    2. Re:Hmmm by PitViper401 · · Score: 5, Funny

      But what about the conjugal visits?!

    3. Re:Hmmm by gutnor · · Score: 1

      If you win millions - you get a big fat check and a senior position in a Wall Street bank, with more check on the way.

      If you lose millions, nothing happens, try again next time.

      If you lose billions, you let the taxpayer deal with the bill and take a year or two of vacation with the savings of previous good years. Try again next time.

    4. Re:Hmmm by dontmakemethink · · Score: 1

      That's it, you fight, it's better that way...

      --

      War as we knew it was obsolete
      Nothing could beat complete denial
      - Emily Haines
    5. Re:Hmmm by supernova_hq · · Score: 1

      If you lose billions, you blame the economy and get bailed out by the government.

      There, fixed that for you.

  14. gfx by RiotingPacifist · · Score: 4, Insightful

    can't this be used in gfx cards, i mean with anti-aliasing and high resolutions it doesn't really matter so much if 1/2 a pixel is #ffffff or #f8f4f0 , hell you can probably even get a pixel entirely wrong for one frame and nobody will care (as long as it doesn't happen too often).

    --
    IranAir Flight 655 never forget!
    1. Re:gfx by retroStick · · Score: 2, Interesting

      I agree. In fact, with real-time photorealistic rendering, these slight deviations would probably make frames look more accurate, since real video is full of low-level random noise.
      The film-grain shader on Left 4 Dead wouldn't be necessary any more.

    2. Re:gfx by Dogtanian · · Score: 1

      Funny you should mention that; as far as I'm aware some graphics cards *do* tolerate these sorts of minor glitches. IIRC, I heard this in connection with a /. article that discussed using GFX chips as general-use processors.

      --
      "Slashdot - News and Chat Sites Deviant". (Click "homepage" link above for details).
    3. Re:gfx by FlyByPC · · Score: 1

      hell you can probably even get a pixel entirely wrong for one frame and nobody will care (as long as it doesn't happen too often).

      You must be new enough here to have never been fragged by a shock spell across a dark room. Flashes of light -- even small ones -- are important, at least in Oblivion.

      --
      Paleotechnologist and connoisseur of pretty shiny things.
    4. Re:gfx by Anonymous Coward · · Score: 0

      Adding random noise to random noise will make it better?

    5. Re:gfx by Anonymous Coward · · Score: 0

      IIRC, then some MIPS processors contain fast versions of some of the more expensive operations (eg. sqrt and div).

      These instructions are not compliant with the usual IEEE floating point specification, but may be adequate for graphics use.

    6. Re:gfx by andrewcharles420 · · Score: 1

      I don't know about ATI/others, but NVIDIA graphics cards have only recently been able to do calculations in double precision (CUDA 2.0 was released ~August 2008). The current hardware implementation doesn't even take full advantage of the architecture (good explanation here: https://www.cs.virginia.edu/~csadmin/wiki/index.php/CUDA_Support/Enabling_double-precision#Performance; that kind of accuracy seems not to have been needed before).

    7. Re:gfx by mdarksbane · · Score: 1

      You won't notice if it is "off", but you will notice if it is inconsistent. It will result in a strangely flashing or pulsating pixel every time something influencing it moves. Think aliasing.

      If you apply it to something a little more important than a single pixel value (like, say, the location and rotation of your camera) you get much more disturbing effects.

      Most current GPU's only work in single precision floating point, and in many(most) it is less than 32 bit precision. This is usually fine for the scale of objects you are dealing with in most video games, but in some types of game (for example, flight sims) it is something you have to make sure you pay attention to when you design your engine.

    8. Re:gfx by Brandybuck · · Score: 1

      Maybe for videos and games, but quite a few of us expect our 2D graphics to be accurate and exact.

      --
      Don't blame me, I didn't vote for either of them!
    9. Re:gfx by DigiShaman · · Score: 1

      With regards to nVidia, this is true of the GeForce line. Not so with the Quadro series however, which is why they have five different driver sets to choose from depending on the main application you work with.

      When using applications like CAD, you do not want any errors/glitches in your work.

      --
      Life is not for the lazy.
    10. Re:gfx by drinkypoo · · Score: 1

      You can specify accurate or fast rendering on either geforce or quadro (my laptop has Quadro FX1500M, my desktop has some janky old nvidia AGP card) and they both do about what you'd expect. Equally true is that no nvidia card up to 8xxx series at least has double-precision operations, they have the data type e.g. in CUDA but they actually only do single precision. Or so I have read... All I know about the Quadro really is that mine is one of the better display cards of the generation, that it has 10bpp but my laptop display panel is only 8bpp, and that HP hasn't updated my driver so I had to go get it straight from nVidia which is an unsupported configuration (they do not officially support mobile Quadro devices in the downloadable driver. I have also had many problems with the linux driver and ended up going back to Windows XP) :(

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
    11. Re:gfx by wITTus · · Score: 1

      Raytracing!

    12. Re:gfx by dreamchaser · · Score: 1

      Yes, you're really going to notice *one pixel* in one out of 50-100 frames per second (sarcasm)

      Graphics cards already do tolerate errors like that, so you've already had those 'off' pixels in your games. Apparantly you haven't noticed.

    13. Re:gfx by Twisted64 · · Score: 1

      It'd work WELL for things like left 4 dead, where that bloody film grain makes an appearance. Turn it way up for the horror games, save the important cycles for A.I. or mass zombie hordes :)

      Or leave it on for the ultimate A.I. experience, where your teammates just randomly shoot you in the head - I guarantee it'll pass the gaming turing test.

      --
      Consciousness is a myth. Trust me.
    14. Re:gfx by Anonymous Coward · · Score: 0

      If you apply it to something a little more important than a single pixel value (like, say, the location and rotation of your camera) you PROBABLY SHOULDN'T BE PROGRAMMING GAMES.
      It's common sense where to use and not use these processors. It's like saying 'multiple cores is nice and all, but what if my data needs to be processed linearly?!?!! OMG?!'

    15. Re:gfx by RiotingPacifist · · Score: 1

      I take it you never use jpegs then?

      --
      IranAir Flight 655 never forget!
    16. Re:gfx by clone53421 · · Score: 1

      1/2 a pixel?

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
    17. Re:gfx by mdarksbane · · Score: 1

      I don't normally feed the trolls, but relax. I was just letting people know that there are limitations to this sort of thing that you have to work around, even when it comes to games. In the camera case, it's generally an easy fix - do whatever transformations you need from world space in double precision on the CPU. From the general opinion here, though ("you never need precision for games") it seemed as though people didn't recognize some of these exceptions that one might have to work around.

    18. Re:gfx by Brandybuck · · Score: 1

      Not when I want accuracy I don't! I only use jpegs for photographic images, NEVER for line art, never for text, never for any onscreen control.

      --
      Don't blame me, I didn't vote for either of them!
  15. Multimedia processor by Gerald · · Score: 2, Informative

    If you're about to join the upcoming avalanche of smartass comments, try reading the UDP-Lite RFC first. For some applications (notably real-time voice and video), timeliness and efficiency are more important than accuracy.

    If this means my music player or phone get more battery life, I'm all for it.

    1. Re:Multimedia processor by ndogg · · Score: 1

      I'm with you there. I want to listen to my music for weeks without having to plug it in at all, especially if I'm camping.

      --
      // file: mice.h
      #include "frickin_lasers.h"
    2. Re:Multimedia processor by mbone · · Score: 1

      Another appropriate comparison would be UDP with Forward Erasure Protection (FEC), which is a probabilistically guaranteed delivery mechanism (i.e., the data will probably arrive in full, but there is no guarantee, for times when accepting that risk is better than requiring delivery).

    3. Re:Multimedia processor by Anonymous Coward · · Score: 0

      I have. You seem to forget the difference between deterministic networking, and deterministic logic/calculations. You can error check all you want when you know you will detect errors, and even interpolate over them, but how do you handle routine byzantine faults as a processor feature?

      I would never agree to program for such a thing - buffer overflows would become routine and uncontrollable (the article talks about the WHOLE processor being non-deterministic, not just the FPU), calculations could drop, and integer overflows could potentially happen randomly. Of course, CRC32's become useless, as they could now fail non-deterministically, and even conventional debugging is pointless, since your application will fail arbitrarily anyway.

    4. Re:Multimedia processor by SoftwareArtist · · Score: 1
      The challenge in making something like that work is specifying where accuracy is required and where it isn't. Consider a video decoder.

      If there's a one bit error in the color of a pixel, no one will notice it.

      If there's a one bit error in the compressed data stream, that could produce a large block of incorrect pixels.

      If there's a one bit error in the address you load the data stream from, you'll get a screen full of garbage.

      If there's a one bit error in the address of a subroutine you call, your program will crash.

      Conventional computers begin by assuming everything needs to be accurate. You can then make a conscious choice to sacrifice accuracy in certain places (by your choice of algorithm) when you're sure it's OK. If this is another way of doing that, it could be useful. For example, you might decide that the content of the frame buffer isn't very important: errors there don't hurt much, and it all gets rewritten 30 times per second anyway. So you could reduce the power to that block of memory, knowing that it will increase the probability of random errors.

      But if you reverse the fundamental assumption - everything is inaccurate except a small set of things that you specifically demand to be accurate - the entire way we write programs would become untenable. I just don't see how that could be made to work.

      --
      "I'm too busy to research this and form an educated opinion, but I do have time to tell everyone my uninformed opinion."
  16. Primality testing by 2.7182 · · Score: 2, Informative

    Random algorithms are used all the time. In RSA for example, random primes must be generated. This is done with an algorithm that probably gives the right answer, which is good enough. The chance that it would fail is so tiny as to not matter.

    1. Re:Primality testing by phoenix321 · · Score: 2, Interesting

      Even more so: we intentionally gather entropy to improve the pseudo random numbers. With intentionally inaccurate CPU cores, we could scrap all that and gather entropy en-passant AND be much faster anyway.

    2. Re:Primality testing by Dahamma · · Score: 2, Insightful

      Yeah, but there is a big difference between "random" and "incorrect".

      The errors resulting from undesirable interactions between transistors are probably a lot less random than a good pseudorandom number generator for these purposes.

    3. Re:Primality testing by Hognoxious · · Score: 2, Insightful

      Random algorithms are used all the time.

      I'm not even sure such things exist. Even if you meant pseudorandom, that still has zero to do with the point under discussion.

      --
      Confucius say, "Find worm in apple - bad. Find half a worm - worse."
    4. Re:Primality testing by Nebu · · Score: 1

      Random algorithms are used all the time. In RSA for example, random primes must be generated. This is done with an algorithm that probably gives the right answer, which is good enough. The chance that it would fail is so tiny as to not matter.

      To get a bit pedantic...

      An "algorithm" in "Turing-computable" (i.e. all algorithms you are running on your x86 processors) sense, cannot be random. These algorithms are always deterministic, but may use as input data which is random or pseudo-random (such as the current system time).

      1: The algorithm you are referring to is "probabilistic", but still deterministic. It takes as input a number and a random seed, and it returns a boolean. "true" means the number provided is definitely prime, and "false" means that the number is nonprime with some (known) non-zero probability.

      2: Further, the algorithm has the property that by repeatedly running that algorithm with a different random seed, you can combine the probabilities such as to reduce the probability that the number is prime arbitrarily as close to zero as you want (but it can never actually reach zero).

      It's this last property which is important for the RSA program: being able to control the computation-time/probability tradeoff. Contrast that with the following algorithm which has the property described in [1], but not in [2]:

      boolean isPrime(int number, random seed) { const knownPrimes = [2,3,5,7]; if (number in knownPrimes) { return true; } return false; }

      Rerunning this algorithm with a different seed doesn't allow you to increase your confidence in the primeness of the given number.

      It's not clear whether the proposed CPU has the analogous property of "2": Is there a way to control the computation-time/probability tradeoff? If not, the applications may be more limited than you think.

    5. Re:Primality testing by Nebu · · Score: 1

      Even more so: we intentionally gather entropy to improve the pseudo random numbers. With intentionally inaccurate CPU cores, we could scrap all that and gather entropy en-passant AND be much faster anyway.

      There are many different types of Random Number Generators (RNGs). We might desire that the RNG be cryptographically secure for example, or we might desire that the RNG has a "nice spread" over all possible values for simulation/game purposes.

      Plus, who's to say that the errors generated by these probabilistic CPUs are not deterministic? (i.e. given the same input, it always generates the same errors).

    6. Re:Primality testing by againjj · · Score: 1

      A "random algorithm" takes the same inputs a non-random algorithm plus an auxiliary input stream. The algorithm makes choices based on the auxiliary stream while producing a result. The algorithm is called "random" as the auxiliary stream is intended to be random. The quality of result is based on the randomness of the auxiliary stream. A random algorithm really is not random; just some of the input is (or at least pseudo-random).

    7. Re:Primality testing by clone53421 · · Score: 1

      Are you describing hardware random implementations? Pseudo-random generators don't really have an "auxiliary" stream that's intended to be random.

      I'm by no means an expert, but I did learn a bit about random number generators when I wrote a lagged Fibonacci generator in assembly... purely for personal enrichment, I should add. ;)

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
    8. Re:Primality testing by againjj · · Score: 1

      No, I'm describing a "random algorithm", not a "(pseudo)random number generator". A random algorithm is not random. It just makes decisions based on a random input, which means the algorithm is only as random as its input. Wikipedia explains it: http://en.wikipedia.org/wiki/Randomized_algorithm

    9. Re:Primality testing by clone53421 · · Score: 1

      Ok, that makes perfect sense now. I thought you were talking about an algorithm to generate random numbers.

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
  17. uhhh.... by girlintraining · · Score: 0, Troll

    NEWS FLASH: Binary consists of 1 and 0. Either the answer is right, or it isn't. "probablistic computing" is another way of saying "sloppy engineering". There is no random, only Zuul!

    --
    #fuckbeta #iamslashdot #dicemustdie
    1. Re:uhhh.... by Dogtanian · · Score: 5, Informative

      NEWS FLASH: Binary consists of 1 and 0.

      NEWS FLASH: People use computers for calculations with more than single-digit binary results.

      "probablistic computing" is another way of saying "sloppy engineering".

      No- insisting on excessive precision where an "almost certainly right to within +/- x%" solution would be more than good enough and much simpler to obtain is known as overengineering.

      I suspect that the financial examples chosen didn't illustrate the point as well as intended (financial companies generally don't like *any* inaccuracy), but that doesn't change the general principle.

      Would you prefer a routing algorithm that gobbled up power and took ages to run for a guaranteed shortest route or one that was far more efficient and 99.9% certain to give a route that was within 3% of the shortest possible distance?

      --
      "Slashdot - News and Chat Sites Deviant". (Click "homepage" link above for details).
    2. Re:uhhh.... by phoenix321 · · Score: 1

      What if good enough really IS good enough? In a fast paced game, would you trade a tenfold increase in graphics speed for having a tiny percentage of pixels being barely noticable off the correct color?

    3. Re:uhhh.... by anss123 · · Score: 1

      What if good enough really IS good enough? In a fast paced game, would you trade a tenfold increase in graphics speed for having a tiny percentage of pixels being barely noticable off the correct color?

      We already do. All graphic cards today have a "performance - quality" slider.

    4. Re:uhhh.... by Anonymous Coward · · Score: 0

      I'll see your Ghostbusters reference ("There is no Dana, only Zuul!") and raise you a reference you get to go figure out:

      "Random produced a dagger and left it in a nearby stomach."

    5. Re:uhhh.... by Twinbee · · Score: 1

      I'd like the option. I'm not sure how gracefully this new fangled probability drive 'degrades' to precision computing...

      --
      Why OpalCalc is the best Windows calc
    6. Re:uhhh.... by Anonymous Coward · · Score: 0

      Surely it should calculate whether the time is better spent working out the route or actually driving. If it takes longer to work out a route, but you still end up there faster, who cares? (Ok, I know that's improbable, but you get the idea)

    7. Re:uhhh.... by Anonymous Coward · · Score: 0

      someting like that would be fine, but my bank balance needs to be precise at all digits all the time. just what we need is it to be acceptable for bank balances to be off by a few cents here and there, then it won't be long before they are lower than they should be 10% more often than higher.

      a bank of america accountant was able to scam nearly a billion dollars if i recall by shaving half a cent off of each transaction, keeping the number reported on the balance rounded up to hide the change. a system like this used for bank balances would provide a perfect cover to hide such activity while making it even more profitable.

    8. Re:uhhh.... by mishehu · · Score: 1

      I suspect that instead of a financial example, where accuracy to the nth position is often times a strict requirement, they should have used a physics calculation. After all, if there were science courses that were very strict about using the proper amount of significant digits, it was physics. Perhaps this processor could be used for physics research, especially if the accuracy level of the processor can be adjusted somehow.

    9. Re:uhhh.... by mlwmohawk · · Score: 1

      NEWS FLASH: People use computers for calculations with more than single-digit binary results.

      Absolutely.

      No- insisting on excessive precision where an "almost certainly right to within +/- x%" solution would be more than good enough and much simpler to obtain is known as overengineering.

      The discussion is about a processer being less accurate. IMHO floating point isn't accurate enough. You still need a fixed point library to do back calculation -- even in this day of 64bit CPUs.

      Would you prefer a routing algorithm that gobbled up power and took ages to run for a guaranteed shortest route or one that was far more efficient and 99.9% certain to give a route that was within 3% of the shortest possible distance?

      And here is the fallacy of "fuzzy" models. Your statement "was within 3% of the shortest possible distance?" How would you guarantee that? How could you know that unless you verified the algorithm?

      It is "engineering" to start at high precision and work toward an acceptable trade-off on a case by case example, but you can't do that if you start off at a low precision.

      Back to your example, you can't "know" you are within 3% if you have not accurately calculated the problem first. The implementation of your argument would be do an exhaustive search once (or periodically) for routing, and then just choose the last router node used from the last edge with child nodes in that vicinity.

    10. Re:uhhh.... by Dogtanian · · Score: 1

      The discussion is about a processer being less accurate.

      Not exactly, the discussion was about trading off accuracy for speed and efficiency. And my comment was specifically a reply to what Girlintraining said.

      And I don't think that *anyone* was suggesting that this processor would be suitable for all possible computer uses.

      The example I gave was hypothetical and pulled out of my backside- and wasn't meant to be anything more than that.

      Back to your example, you can't "know" you are within 3% if you have not accurately calculated the problem first.

      You could use mathematical/statistical means to prove that in (from my original example) 99.9% of situations the answer returned would be within 3% of the most efficient answer. I can't say more than that because it was a hypothetical algorithm(!)

      However, the fact is that although many problems in computer science can be proven to be horribly slow to get the optimal answer, there often exist far more efficient algorithms which will provably return a solution that's within a small percentage of the optimum one.

      That's not using probabilistic methods, IIRC- a probabilistic algorithm would, I assume, only be able to be proven to work in a statistical (high) percentage of a very large number of runs. But that would probably be acceptable for non-life-threatening uses.

      --
      "Slashdot - News and Chat Sites Deviant". (Click "homepage" link above for details).
    11. Re:uhhh.... by tftp · · Score: 1

      You could use mathematical/statistical means to prove that in (from my original example) 99.9% of situations the answer returned would be within 3% of the most efficient answer. I can't say more than that because it was a hypothetical algorithm(!)

      Engineering already uses partial derivatives to understand how errors of inputs affect the output. However an algorithm is far more than a single function, and complete mathematical analysis of even a small algorithm may be too difficult (or too expensive, or too lengthy.) In some algorithms errors will be canceling each other out, in other algorithms errors will be magnifying each other, with end result being completely wrong. Take many sorting algorithms, for example - they really hate to compare values more than once, and if the result of a comparison is randomly wrong, just once, then the resulting array is not sorted correctly.

    12. Re:uhhh.... by Dogtanian · · Score: 1
      Then they should only use the processor in places where its limitations are not an issue. I certainly wouldn't suggest that it was appropriate for every purpose.

      complete mathematical analysis of even a small algorithm may be too difficult (or too expensive, or too lengthy.

      Or impossible, if the Halting Problem is anything to go by?- or does that only apply to analysis by a Turing Machine?

      --
      "Slashdot - News and Chat Sites Deviant". (Click "homepage" link above for details).
    13. Re:uhhh.... by mlwmohawk · · Score: 1

      Take many sorting algorithms, for example - they really hate to compare values more than once, and if the result of a comparison is randomly wrong, just once, then the resulting array is not sorted correctly.

      While I don't think the approach being discussed is a good idea, most sorting algorithms are merely concerned with = -1, 1, 0 respectively.

    14. Re:uhhh.... by tftp · · Score: 1

      Or impossible, if the Halting Problem is anything to go by?- or does that only apply to analysis by a Turing Machine?

      No, not impossible in general case, since a simple algorithm can be defined as "c := a+b" and all we need to do here to analyze is to check the ADD operation in the CPU, if it introduces any errors. If it does, write them down.

      Some of more complex algorithms can be also analyzed; what you do there is you introduce errors into all results. Then when you use these results as inputs into other modules you use the same method, plus modules' input errors, to determine errors in their output, and so on. As you can see, this can quickly become a complex task - and we haven't started talking about loops yet. I'd say such analysis of any common algorithm (or even worse, an uncommon one) will be impractical.

      Nevertheless, brain operates imprecisely, just like this proposed CPU. So maybe there is something to it... but not among algorithms that are designed for precise calculations. Things like AI, image recognition, video/audio processing can definitely trade some certainties for something else (element density and connectivity is probably most wanted in AI.)

    15. Re:uhhh.... by tftp · · Score: 1

      While I don't think the approach being discussed is a good idea, most sorting algorithms are merely concerned with = -1, 1, 0 respectively.

      I was thinking about an error that a CMP command may introduce when comparing close values. The order of elements then will be wrong, and an eBay customer who bid the highest may lose the auction (for example.) This is a reasonable concern because in many implementations CMP is implemented as SUB with the result ignored but flags set, for the subsequent conditional operation to act upon.

    16. Re:uhhh.... by mewshi_nya · · Score: 1

      I'm going to guess "Mostly Harmless"

    17. Re:uhhh.... by meson2439 · · Score: 1

      NEWS FLASH: People use computers for calculations with more than single-digit binary results.

      If you remember binary, it's like this

      10101=(1*2^0)+(0*2^1)+(1*2^2)+(0*2^3)+(1*2^4)

      If noise are not controlled in the processor, each bit will be induced to change although the error could be compounded on the bits of least significant digits. So you might get 10111 or 10100 or some other combination for the last two bits. This will result in error of around +-3.

      Accuracy is more important in calculating the result of bit operators where errors are being magnified. Another important field is bit logic, where a simple error could be disastrous.

      This will result in reduced calculation to mitigate error propagation. Thus complex calculation can never be done. For music and video, we could be probably use less than 1 byte for each represented number and the calculations are quite direct (not much use of bit logic and very little error propagation). Another problem that might occur is that you can never do an exact loop ever again which is also a no problem for music. But unlike mp3 where the error are quite controlled, I bet a music player using this noisy processor will produce some of the shittiest music you ever heard and you have to listen to it raw (decompression introduce errors). This will incur extra storage space.

      It will sound even worse when you go to a hotter climate. But it might be acceptable for ringtones I think. At it's best, it might sound like your analog radio. Most old timers think it was good enough. But on a plus side, DRM cannot be implemented on such device.

    18. Re:uhhh.... by sketerpot · · Score: 1

      Then they should only use the processor in places where its limitations are not an issue. I certainly wouldn't suggest that it was appropriate for every purpose.

      That's exactly what they're proposing: a system-on-a-chip with a conventional processor for most of the application and an on-die probabilistic coprocessor for the calculations that can be done in a probabilistic way. The only people talking about approximate accounting and other such inappropriate uses are Slashdot "smart"-asses.

    19. Re:uhhh.... by Dogtanian · · Score: 1

      You make so many assumptions about how the chip operates and what it is *intended* to be used for that your argument is virtually meaningless.

      While the article mentions random errors, it doesn't specifically say that the chip relies on noise or how these random errors are generated and used. Until we know this, any reasoning about bits such as your comment is (at best) speculation of limited meaning.

      It's incredible the number of comments for this story that make kneejerk assumptions about these things when the original article doesn't say enough to infer them. And anyone with some common sense would assume that the people who designed the chip *might* have had some idea what they were doing and had considered the obvious flaws which every random basement-dwelling Slashdotter takes great delight in pointing out and seems to think they missed. (Despite the article not providing us with enough information to reach this conclusion).

      --
      "Slashdot - News and Chat Sites Deviant". (Click "homepage" link above for details).
    20. Re:uhhh.... by petermgreen · · Score: 1

      Or impossible, if the Halting Problem is anything to go by?- or does that only apply to analysis by a Turing Machine?
      It only applies to analysis *of* a turing machine or a similar hypothetical construct with infinite states. For a finite state machine given enough time the machine must end up in either a single state or an infinitely repeating sequence of states. So if you simulate the machine until you see a repeated state you will know whether the state/repeating sequence of states is one that you would consider halted.

      Of course for something as complex as a computer the total number of states is insanely high and as such there may be no repeats in the lifetime of the universe.

      --
      note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register
    21. Re:uhhh.... by Aphoxema · · Score: 1

      What the article really brought to mind was trajectories in games. FPS's, despite the classification, don't have a lot of shots to calculate, but something like Supreme Commander would definitely stand to save on trajectory calculation where hundreds out thousands of 'bullets' can be 'flying' at once.

      Maybe it could apply to Fourier transforms too, but I don't dare claim to know the process behind them.

      --
      "Most people, I think, don't even know what a rootkit is, so why should they care about it?"
    22. Re:uhhh.... by meson2439 · · Score: 1

      Duhh... read the post... Notice how engineers overcome noise??? yup... by INCREASING VOLTAGE. If you have any experience with electronics at all, you will agree with me that the only reason is to increase SNR (Signal noise ratio). In this context, noise refers to white noise.

      Even if you want to worship the guy, a little common sense and deductions doesn't hurt. That's how scientific process works. The guy (in the story) is also at fault for not publishing it first before making a claim. But maybe you're a lawyer or from the sales department. So, the whole peer review rant might not make sense to you.

    23. Re:uhhh.... by Dogtanian · · Score: 1

      Notice how engineers overcome noise??? yup... by INCREASING VOLTAGE. If you have any experience with electronics at all, you will agree with me that the only reason is to increase SNR (Signal noise ratio). In this context, noise refers to white noise.

      That as may be, who mentioned voltage? You, and you appear to be *assuming* that they'll simply keep everything else the same and drop the voltage of the chip increasing the noise. Assumption.

      Even if you want to worship the guy

      I already said there wasn't enough information to say whether or not this was a good idea. So why the hell you assumed I would "worship" the guy is unclear.

      Oh, hang on.... it's entirely clear. You're one of those people who assumes that criticism of a badly-formulated attack on X implies that the critic supports X. Or else just likes to use that flawed logic as the basis of an attack.

      But maybe you're a lawyer or from the sales department. So, the whole peer review rant might not make sense to you.

      See, now you're just resorting to poorly-veiled insults. That's not even an ad hominem attack, it's just third-rate name calling. While it says nothing about me, it says a *lot* about you.

      --
      "Slashdot - News and Chat Sites Deviant". (Click "homepage" link above for details).
  18. No company will use it by whitroth · · Score: 0

    When I was first studying programming, back when we had to use magnets to write 1's and 0's (ok, punch cards), we heard about the unnamed bank, somewhere in the sixties or early seventies, where a programmer had coded so that fractions of a penny were rounded down, always, and the difference showed up in an account he'd set up. He made many tens of thousands of dollars (and back then, that was real money) before he was caught. Now with orders of magnitude more transactions, there is no way any company would use this kind of probability.

    And if you want to argue this, I suggest you go talk to the bean counters where you work.

            mark

    1. Re:No company will use it by BikeHelmet · · Score: 1

      But think of the power savings! :P

      Honestly, this sounds more like a DSP replacement. Most computers need exact math, but some don't.

    2. Re:No company will use it by nycguy · · Score: 1

      There are plenty of calculations in finance where only a few digits of accuracy are needed, either because a price is expressed in only a few digits (e.g., an option value being $1.46 is fine as opposed to $1.46189503 which will get rounded to $1.46 anyway) or because the inputs to the model have large errors themselves (e.g., a volatility of 21% which could just as easily be 20% or 22%, making the less significant digits meaningless anyway). These calculations also happen to be the ones that are done in real time throughout a trading day with countless cycles being wasted on unnecessary accuracy.

      In a larger context, there are a ton of financial products that are valued using Monte Carlo simulations. By definition, you've already got probabilistic inaccuracy there. Why not make the individual Monte Carlo paths a bit less precise and just run a lot more of them, since it's the average that really counts?

      Now, it could be that what I'm asking for here is really adaptive/selectable precision, but the point is that not all calculations need to be 15-digits accurate or even reproducable to be useful.

    3. Re:No company will use it by kwikrick · · Score: 1

      well, lets argue it a bit anyway, for fun.

      If fractions are rounded up and down randomly, I mean with an equal chance, then there should be no overall loss or gain, in the long run. Of course, there might be outliers, some accounts might get shorted a bit more, some might get lucky, some people may try to game the system. Sounds just like real life. It wouldn't make such a big difference.

      Still, you're right, nobody would accept such a system, because we all like the illusion of control.

      --
      assignment != equality != identity
    4. Re:No company will use it by Gerald · · Score: 1

      And if you want to argue this, I suggest you go talk to the bean counters where you work.

      Bean counters won't use this (at least I hope not). Telecom engineers will.

    5. Re:No company will use it by a+dark+blue · · Score: 1
    6. Re:No company will use it by Qzukk · · Score: 1

      an option value being $1.46 is fine as opposed to $1.46189503

      It is until someone buys 1000000 of them.

      --
      If I have been able to see further than others, it is because I bought a pair of binoculars.
    7. Re:No company will use it by alannon · · Score: 1

      Actually, this is very common among bankers and accountants. I believe that most spreadsheets do this as well.

      http://en.wikipedia.org/wiki/Rounding#Round-to-even_method

      It's not exactly 'random' but the system is designed to average out the errors.

    8. Re:No company will use it by Smallpond · · Score: 1

      It's called the Salami Technique.

    9. Re:No company will use it by Anonymous Coward · · Score: 0

      Since then they invented "bankers rounding" and now profit institutionally by setting prices which put averages in their favor.

    10. Re:No company will use it by Anonymous Coward · · Score: 0

      And then he went to federal pound-me-in-the-ass prison?

  19. Sacrifices are expected by LiquidCoooled · · Score: 4, Interesting

    I have spent the last 9 months coding up a dynamic scalable UI for the nokia tablets.

    I have had to make huge compromises to accuracy to obtain the desired performance.

    I had the choice of using the full featured (but slow) widget sets and graphical primatives which existed already, or find a way to make it work as I expected it to.

    The results have left people breathless :)

    take a look here: http://www.youtube.com/watch?v=iMXp0Dg_UaY

    --
    liqbase :: faster than paper
    1. Re:Sacrifices are expected by Anonymous Coward · · Score: 0

      And this is related to the story how?

    2. Re:Sacrifices are expected by Anonymous Coward · · Score: 1, Insightful

      It's related to the story because it's an example of increasing performance at the cost of reducing accuracy.

    3. Re:Sacrifices are expected by syousef · · Score: 1

      I have had to make huge compromises to accuracy to obtain the desired performance.

      I watched your video and I don't get it. Exactly what compromises have you made? If you're talking about rough or heuristic scaling of fonts that's not the same as compromising accuracy on a processor. You're not going to pull up the calendar for the 14th when you click the 15th for instance.

      --
      These posts express my own personal views, not those of my employer
    4. Re:Sacrifices are expected by Anonymous Coward · · Score: 0

      Because he achieved good results by trading accuracy for performance. Your reading comprehension skills are astonishingly poor.

    5. Re:Sacrifices are expected by ljw1004 · · Score: 5, Funny

      That was a very confusing video. What I learned from it: you haven't done some stuff, Zoom Fish!, widgets, Zoom Fish!, behind schedule, zoom, Fish!, widget framework, Fish!

      I guess it's a system that lets you zoom in on fish?

    6. Re:Sacrifices are expected by LiquidCoooled · · Score: 1

      if for nothing else then it should be useful for at least aquarium owners ;)

      you haven't done some stuff

      You are right, I've done nothing

      behind schedule

      Personal schedule, this is an open source project I have a fulltime job and a family as well.

      widget framework

      :) yes, I think what I haven't achieved may be useful for others to work with.

      What I use it for will be upto me, what you people want to use it for is upto your imagination.

      Its an idea I have decided to follow up on.
      If it doesn't interest you thats ok.

      --
      liqbase :: faster than paper
    7. Re:Sacrifices are expected by Anonymous Coward · · Score: 0

      Nice job! :)

    8. Re:Sacrifices are expected by da+cog · · Score: 1

      You missed his point. He wasn't criticizing your project, he was criticizing the way that your video presented it. Your video may have been good for the audience for which it was intended -- i.e., people who were already familiar with your project -- but for people who have never heard of your project before it was a bit incoherent and rambling which made it confusing to figure out what it does. (Nothing wrong with that, of course, since you are doing this in your free time fun, but I just figured you should be aware of how you were coming across in case you decided to care about it.)

      Also, if I may humbly make a suggestion: as a general rule, when making a presentation it almost never helps you to throw in apologies, since you are more likely to remind people that they should be annoyed at you about something than you are to assuage people who already are annoyed at you. For example, there have been a couple of occasions I can think of off the top of my head where somebody said, "I know, I am sorry that I am horrible at drawing things!" as they were making drawings on a board, and it was only at the moment that I realized that, yes, indeed, his drawings were terrible -- and the irony is that if he hadn't said anything, then I probably would not have noticed since I was too busy paying attention to what he had to say. :-)

      Anyway, best of luck with your project, and maybe to help the GP and the general Slashdot audience you could post a little bit if you want on what your project is actually about so that we could know why what you are doing is awesome. :-)

      --
      Snarkiness is inversely proportional to wisdom because it emphasizes feeling right rather than being right.
    9. Re:Sacrifices are expected by koutbo6 · · Score: 1

      omg .. did youtube get /.ed?

      --
      You speak London? I speak London very best.
    10. Re:Sacrifices are expected by Blissett+Luther · · Score: 1

      Don't listen to him :) You're a genius! Good work. It's really impressive (and useful)

    11. Re:Sacrifices are expected by BikeHelmet · · Score: 1

      14 and 15 are integers. CPUs require less transistors to handle those, which means less chance to lose bits. If the CPU is well designed, integers will still be 100% accurate, but floating point will just be "more inaccurate + much faster".

      I'd hope there was the option to opt-in. (maybe some instructions that tweak the behaviour?)

      For stuff like handheld UIs, getting RGB values wrong by even 2 bits shouldn't be visible or matter.

    12. Re:Sacrifices are expected by ljw1004 · · Score: 1

      Sorry, the post was rude of me. The zooming and dragging looks cool as heck. I just think that your presentation was poor: after watching it I had a good idea of what you hadn't done, but no idea at all about what you had done nor what it was good for (nor even what it was for). Also your repeated "nervous tic" of zooming in on the fish was distracting and didn't add anything.

      Conclusion: the name "liqbase" is now in my head, so that next time it's mentioned I'll look into it, but I didn't learn anything here.

    13. Re:Sacrifices are expected by supernova_hq · · Score: 1

      Wow, very impressive. I just installed it on my N810 and I think your work is amazing. I've always disliked how badly maemo treated fingers, and I hope people start to notice your work.

      Are you planning on keeping this as a standalone client, or are you planning on turning it into a hildon replacement? The scrolling, etc in your demo app is amazing and I would love to see it implemented elsewhere (browser, image viewer, etc).

      Best of luck.

    14. Re:Sacrifices are expected by LiquidCoooled · · Score: 1

      the recent pictures module for the released liqbase client has just been inserted this evening.

      http://liqbase.net/liq.20090208_205336.lib.scr.png

      It zooms into the cluster of images as they are shown in the current liqbase.

      once you have a screen of images, you can click to zoom in exactly the same way.

      I realise my presentation is poor, I am simply extremely pleased with how the UI is shaping up and just wanted to tell people :)

      --
      liqbase :: faster than paper
    15. Re:Sacrifices are expected by supernova_hq · · Score: 1

      I noticed that that part was missing, is there any chance this will make it into the repositories soon, or this there another private repository I can add to get the new stuff?

      I would be very interested in possibly becoming a beta-tester, I use my N810 for college stuff, so any productivity apps I could test would be amazing. I would have no problem in sending in bug reports every now and then if you like.

    16. Re:Sacrifices are expected by supernova_hq · · Score: 1

      I noticed that that feature was missing in the repo-installed version. Is there another repo I can add to get the newer versions?

      I am also interested in becoming a beta-tester for you if you like. I use my N810 for college stuff all the time and have been looking for something like this for a while now. I would love to test out new builds and send you feedback on a regular basis.

      PM me if you are interested in acquiring another beta tester.

    17. Re:Sacrifices are expected by Anonymous Coward · · Score: 0

      Conclusion: the name "liqbase" is now in my head, so that next time it's mentioned I'll look into it, but I didn't learn anything here.

      He's "growing the brand."

    18. Re:Sacrifices are expected by clone53421 · · Score: 1

      For stuff like handheld UIs, getting RGB values wrong by even 2 bits shouldn't be visible or matter.

      To test this theory, I'm currently writing a video driver that simulates an error by XORing the R, G, and B values of each pixel with 11000000.

      Ok, not really.

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
    19. Re:Sacrifices are expected by LiquidCoooled · · Score: 1

      come visit #maemo or #liqbase on freenode :)

      --
      liqbase :: faster than paper
  20. Suitable for streaming media??? by Anonymous Coward · · Score: 2, Funny

    I'd like to see executives at CBS explain how nipples showed ON TOP of a superbowl performer's outfit.

    Talk about a wardrobe malfunction.

    I can see the defense now:

    Your honor: We ran probabilistic tests with out processors, and while we couldn't really duplicate the problem, we were able to show a penis during one test run. We'd really like to show it to you, but Ms. Jackson has stated that she would quote "Sue us into the ground" unquote.

    1. Re:Suitable for streaming media??? by Anonymous Coward · · Score: 0

      we were able to show a penis during one test run.

      yeah, at http : // peniz.notlong.com

  21. Nothing new here... by chill · · Score: 3, Insightful

    Isn't that essentially what JPEG, MPEG and every other lossy codec or transform does?

    --
    Learning HOW to think is more important than learning WHAT to think.
    1. Re:Nothing new here... by kmac06 · · Score: 1, Interesting

      Yes. Except now it's done in hardware. So no.

    2. Re:Nothing new here... by John+Hasler · · Score: 1

      No. Those are lossy but deterministic.

      --
      Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
    3. Re:Nothing new here... by chill · · Score: 3, Interesting

      There have been dedicated MPEG encoding and decoding chips for many years. DXR3 comes to mind.

      I think the only new twist is applying the idea to general calculations as a whole as opposed to a specific function or set of functions in software. An interesting idea. Maybe we'll end up with double-precision, single-precision and ballpark floats.

      --
      Learning HOW to think is more important than learning WHAT to think.
    4. Re:Nothing new here... by osu-neko · · Score: 1

      No, the new thing here is that, using this technology, you could make the next-gen DXR3 much faster while using a fraction of the power.

      --
      "Convictions are more dangerous enemies of truth than lies."
    5. Re:Nothing new here... by Anonymous Coward · · Score: 1, Informative

      JPEG and MPEG are more about a tradeoff of accuracy for space, not a tradeoff of accuracy for speed or for electricity.

    6. Re:Nothing new here... by drinkypoo · · Score: 1

      JPEG et al create an approximation based on what image is convenient to produce. The same is true of all lossy video compression technologies up to (?) and including fractal compression. This would produce a result which was, well, close enough for some purposes. The A/V stuff is the prime example. Another fantastic example would be robotics which work more like the human body. If you could somehow derive the same benefits producing a memory cell which would produce a result "close enough" at a similar benefit in speed and energy efficiency then you'd really have something. You could implement a muscle memory-like system quite adequately with "close enough" results. It might also be extremely useful in the area of vision processing.

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
    7. Re:Nothing new here... by clone53421 · · Score: 1

      That's what I was going to say, too, but then I remembered that GIF and JPEG were designed to make webpages load in reasonable lengths of time over dial-up.

      (And yes, GIFs are lossy – in a sense: they aren't compressed with an analog function like JPEG, but they are compressed into a digital – i.e. discrete – colour space, and a relatively small one at that. Try saving a true-colour bitmap as a GIF and then tell me information wasn't lost.)

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
  22. Games? by ndogg · · Score: 3, Insightful

    I could definitely foresee this being used in game systems, especially for graphics.

    As long as it mostly looks right, that's all that really matters.

    --
    // file: mice.h
    #include "frickin_lasers.h"
    1. Re:Games? by sbayless · · Score: 1

      And in-game physics, where performance is hugely important (and expensive), whereas the exact floating point accuracy of a given force will make a negligible difference. Most rigid body physics systems that you'd find in a game will settle towards an equilibrium regardless of small random perturbations anyways. And many physics simulators introduce this kind of slight randomness in the first place, so there really is nothing to be lost here.

    2. Re:Games? by TheSoepkip · · Score: 1

      There are parts in games that rely on accurate results. Games using deterministic networking, require connected computers to be sync. To test for synchronized states, games usually abstract the overall state of the game as a number. If the connected computers come up with numbers that are the same, the game is supposed to be in sync. If the numbers are different, it may indicate one or more computers are lagging behind.

      Even in today's games, it can be quite tricky to get these numbers right. Multi core processors and minor differences in hardware may result in hard to spot diverging execution orders and as such could result in desyncs.

      Graphics may seem like a suitable candidate, but there are parts of the graphics that maintain a state. In those parts, you may not want to introduce too much error as it may carry over (numerical drift) and need some error-counter code or code resets.

      Games nowadays already make trade offs between accuracy and speed and I could see this work as an additional tool for optimization. However I'm afraid that it will not be as trivial as it sounds. I wouldn't be too surprised if it resulted in similar challenges (and advantages) as multithreading is giving us now...

    3. Re:Games? by Anonymous Coward · · Score: 0

      No, that's wrong. Games already suffer from things like rounding errors. Returning a single value that is a bit off is fine, but repeatedly using inaccurate values, as is done per game tick, results in major bugs.

      FYI, in order to get a game approved for sale on a console system, it has to pass a minimum of 8 hours on idle tests. Even without a wonky processor, I've seen games where walls and objects started moving around in the game world of their own accord, as a manifestation of rounding errors. Those, however, can be controlled in software. If the error is generated from hardware, this kind of chip will NOT be acceptable for any serious use in games, and people need to stop suggesting that it would be. What people tend to forget is that modern games are, essentially, giant 3D physics engines. If anything, they are *more* demanding than other applications when it comes to accuracy and hardware integrity.

      Even if you limited the use to graphics rendering, ask yourself, what's the error rate multiplied by the number of pixels on screen? How many blinking off-color pixels are you willing to put up with? For comparison, read forum posts by PSP owners who have one dead pixel on their LCD and see how much consternation it causes them. Now imagine if it moved around and changed colors with each tick and there were more of them. The effect, I imagine, would be like that of aged film, where due to certain constraints you might not get any particular pixel standing out, but the image as a whole seems to slightly fade in and out because each pixel is oscillating between being a little too high and a little too low.

      This chip is wholly unsuitable for gaming, or by the sounds of it, anything involving graphics. Now if he's trying to sell the chip for use in headless servers, or as an onboard decoder for something like a network card, there might be possibilities there.

    4. Re:Games? by mdielmann · · Score: 1

      As long as it mostly looks right, that's all that really matters.

      In fact, mostly right may be an improvement. Remember when CGI first came out in movies, and one of the main flaws was that things looked too smooth, too perfect? Imagine things being less than 'perfect' as a function of the rendering as well as a function of the texture mapping?

      --
      Sure I'm paranoid, but am I paranoid enough?
  23. A Safety Sticker ? by mbone · · Score: 1

    So, what, future computers may come with a big sticker :

    WARNING : Should not be used in life-critical calculations.

    On the other hand, if the errors are really rare and random, and he can make chips 7 times faster at 1/30th the power drain, then you could array 3 such chips at 7 times the speed and 1/10 the power usage, and do your computations by majority vote.

    1. Re:A Safety Sticker ? by Anonymous Coward · · Score: 0

      Obviously, you realize that that just makes the errors 'more rare', it doesn't eliminate them, so you are back to square one (rare and random errors).

    2. Re:A Safety Sticker ? by ToasterMonkey · · Score: 1

      So, what, future computers may come with a big sticker :

      WARNING : Should not be used in life-critical calculations.

      You mean something along the lines of this?

      "The Software is for entertainment and general informational purposes only and is not designed, intended or licensed for use in hazardous or critical environments requiring fail-safe controls including, but not limited to, the design, construction, maintenance or operation of nuclear facilities, aircraft navigation or communication systems, air traffic control, life support or weapons systems. THE COMPANY SPECIFICALLY DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR SUCH PURPOSES."

      Those types of disclaimers are already more common than you probably realize. There are PLENTY of existing reasons consumer PCs & software shouldn't be used in such situations. This one was pulled from the license agreement for a Weather Widget. You'll probably find one in your computers manual, or the component vendors websites if you built it.

      http://us.shuttle.com/Scgsupport/Policy_Accessories.html
      There's another one.

      From a hardware waranty:
      "YYY does not warrant that the operation of the product will be uninterrupted or error-free."

      I think the detailed ones are mostly in software license agreements . You can always write your own software though, and be amazed when it fails to do what they never guaranteed it would do.

    3. Re:A Safety Sticker ? by Anonymous Coward · · Score: 0

      So, what, future computers may come with a big sticker :

      WARNING : Should not be used in life-critical calculations.

      The data sheets for almost every semiconductor device manufactured in the last 50 years has a disclaimer like this.

      On the other hand, if the errors are really rare and random, and he can make chips 7 times faster at 1/30th the power drain, then you could array 3 such chips at 7 times the speed and 1/10 the power usage, and do your computations by majority vote.

      Just remember to throw an exception when the three answers are all different.

      This is one of the things that the Space Shuttle computers do, and why they kept failing in the early 80's, delaying launch after launch.

    4. Re:A Safety Sticker ? by clone53421 · · Score: 1

      then you could array 3 such chips at 7 times the speed and 1/10 the power usage, and do your computations by majority vote.

      Where's my minority report, damnit?!

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
  24. I Call BS by Shuh · · Score: 1, Redundant

    Bits are bits. There's no guarantee that a "low power" chip will only mess up the low-order bits of a number.

    What is this guy smokin'?

    1. Re:I Call BS by Oidhche · · Score: 1

      More importantly, how do you ensure that only data is messed up? Flipping a bit of data might be acceptable. Flipping a bit of code probably isn't.

    2. Re:I Call BS by Anonymous Coward · · Score: 0

      There's no guarantee that a "low power" chip will only mess up the low-order bits of a number.

      That was neither implied nor said anywhere. You're a moron.

    3. Re:I Call BS by Dogtanian · · Score: 1

      There's no guarantee that a "low power" chip will only mess up the low-order bits of a number.

      Yeah- you spotted the obvious issue that those guys never *ever* would have taken into account before starting work on their design. I hereby nominate you for the Nobel prize.

      The article really doesn't make clear how the chip works, what the probabilities are, etc. so if you're able to come to that conclusion you either know more about it than me, or you're just sitting typing pat answers into Slashdot.

      Oh, and if you want to be pedantic there's no *guarantee* that *any* computer will work correctly- it could get bombarded by enough cosmic rays to generate uncorrectable memory errors.

      --
      "Slashdot - News and Chat Sites Deviant". (Click "homepage" link above for details).
    4. Re:I Call BS by Anonymous Coward · · Score: 0

      More importantly, how do you ensure that only data is messed up? Flipping a bit of data might be acceptable. Flipping a bit of code probably isn't.

      Windows users wouldn't notice.

    5. Re:I Call BS by Anonymous Coward · · Score: 0

      Maybe they designed their chip so that high order bits are computed with slow, robust transistors, and low order bits with fast, flaky transistors.

    6. Re:I Call BS by Guido+von+Guido · · Score: 1

      Oh, and if you want to be pedantic there's no *guarantee* that *any* computer will work correctly- it could get bombarded by enough cosmic rays to generate uncorrectable memory errors.

      I just cover my computers with my used tin foil hats. Never had a problem with cosmic rays!

    7. Re:I Call BS by Nebu · · Score: 1

      Bits are bits. There's no guarantee that a "low power" chip will only mess up the low-order bits of a number.

      • Any Turing-computable algorithm you can implement in software, you can also implement in hardware
      • Isaac Newton, John Carmak, and others, have implemented various Turing-computable algorithms which approximate values of square roots, integrals, etc. which only mess up the "low-order" bits of a number.
      • Therefore, it is possible to design in hardware a chip which implements instructions that only mess up the low order bits of a number.
    8. Re:I Call BS by Nebu · · Score: 1

      More importantly, how do you ensure that only data is messed up? Flipping a bit of data might be acceptable. Flipping a bit of code probably isn't.

      Presumably, the probabilistic CPU still functions on the basic principles of the "fetch-execute cycle". That is, it has a dedicated instruction register (IR) and a dedicated program counter (PC), and several other registers for actually performing the calculations.

      By putting different electromagnetic noise standards on different registers, you can ensure that only certain registers suffer from errors.

      Obviously, there's a lot of handwaving and missing details here, but hopefully it's a bit clearer how to ensure only data has inaccuracies, and instructions won't.

    9. Re:I Call BS by Anonymous Coward · · Score: 0

      Yeah, the basic way of thinking about it seems to imply that you're likely to mess up the higher order bits anyways. Think about any sort of adder, you always get the Least Significant Bits calculated first and it's the later ones that are likely to mess up if you just shorten the clock and hope the last few bits come in mostly correct, most of the time.

    10. Re:I Call BS by Anonymous Coward · · Score: 0

      Adders don't work like that anymore. Hint: there are more than N bits in a N-bit register.

    11. Re:I Call BS by Anonymous Coward · · Score: 0

      The low power chip will only mess up a small number of calculations. Say it messes up 1/10000 and gets 9999/10000 right, with an increase in speed by 7 and a a decrease in power by 30.

      With a some extra registers and logic you could for example run the same calculation several times and compare the results intelligently, until you are sure that the most significant bits are correct.

      Of course, the extra registers and logic for the error check will increase power quite a bit - linearly with switching activity of the transistors - but you start at 1/30 of conventional power and go from there...

    12. Re:I Call BS by dontmakemethink · · Score: 1

      Bits are bits. There's no guarantee that a "low power" chip will only mess up the low-order bits of a number.

      But what if the high-order bits were processed on a core with higher power and the lower-order bits were processed by a lower-power core? I don't know if that's possible yet, but that's one way of load-prioritizing.

      --

      War as we knew it was obsolete
      Nothing could beat complete denial
      - Emily Haines
    13. Re:I Call BS by sketerpot · · Score: 1

      This guy's soon-to-be-unveiled chip uses several different voltage levels. Higher voltages are used for more significant bits, and vice versa. There's your guarantee that the more significant bits will be less error-prone.

  25. Cool for my entertainment by hackingbear · · Score: 1

    Wow... soon, I will be able to comprehend music and video at 7x the standard playing speed! Wonderful!

  26. My bank yould love this by Celc · · Score: 2, Interesting

    I'm sure my bank would love to argue they at least got the 13 right as they skim a penny of every transaction. I'm sure this the most awesome thing since sliced bread, but can we please avoid trying too argue this from the point of peoples bank accounts when it introduces random error.

  27. What a waste of grant money... by gavron · · Score: 2, Insightful
    Processors that provide different output for the same input cannot be used for anything that wants predictable output.

    They can not be used for ANY result that is later used by anything else -- after all, data based on bad data yields bad results.

    Next thing you know, some offshore manufacturer will use the "imprecise" (cheaper) chips instead of the "accurate" ones, and simple things we depend on everyday will fail in wonky ways.

    A bit-flip on a microwave will make a 30-second timer not expire at 0, and keep going at 99:99 and burn the food.

    A bit-flip on a home heating circuit will make 70F appear to be a target heat of 6F and never turn on.

    A bit-flip on an MP3 player would have it skip from 65 seconds into the song to 134 second into the song.

    These are all results if just ONE BIT were to flip JUST ONCE. The processor described would UNPREDICTABLY and RANDOMLY do worse than actually flip one bit.

    What's next -- they'll put three processors in each device and when two of them agree they'll go for it? "Voting Processing" is bs.

    E

    1. Re:What a waste of grant money... by cnettel · · Score: 2, Insightful

      Any system which fails permanently due to a single bit error is unstable and not robust (in the numeric sense). If the system is really critical, you should better be ready for bit errors.

      This approach is basically similar to what would be required in analog systems. After all, analog engineering was quite possible. The main of the meat in decoding MP3 is not about seeking in the stream, it's a lot of Fourier and postprocessing of the waveform -- loss there can be completely acceptable.

    2. Re:What a waste of grant money... by MobileTatsu-NJG · · Score: 1

      A bit-flip on a home heating circuit will make 70F appear to be a target heat of 6F and never turn on.

      Who said anything at all about bit-flips? You and the dudes that wasted their mod-points on your post need to re-read the summary.

      --

      "I like to lick butts!" by MobileTatsu-NJG (#32700246) (Score:5, Informative)

    3. Re:What a waste of grant money... by Rockoon · · Score: 2, Interesting

      I am reminded of how some circuits such as sorting networks are designed with redundancy such that a certain amount of sub-component error is tolerable. They will still sort their inputs even if multiple sub-components get their output wrong.

      It seems to me that we have already been designing things in a probabalistic manner.. all that these new guys are doing is allowing the error tolerance to be much more liberal.

      --
      "His name was James Damore."
    4. Re:What a waste of grant money... by Nebu · · Score: 1

      Processors that provide different output for the same input cannot be used for anything that wants predictable output.

      They can not be used for ANY result that is later used by anything else -- after all, data based on bad data yields bad results.

      I think you're conflating "unpredictable output" with "bad output". There's lot of applications where unpredictable output is tolerable, if not outright desirable. Games is one obvious example. Decoding any lossy data (pictures, music, video, etc.) is another.

      VoIP applications, for example INTENTIONALLY add random noise to the voice calls being transmitted to enhance user experience. See Comfort Noise. This is a situation where we WANT random errors to occur in the output.

    5. Re:What a waste of grant money... by ymgve · · Score: 1

      Any system which fails permanently due to a single bit error is unstable and not robust (in the numeric sense). If the system is really critical, you should better be ready for bit errors.

      Newsflash - 99.99999999% of all CPUs in use won't tolerate bit errors. Get a jump address or opcode wrong, and the program you're running is toast.

    6. Re:What a waste of grant money... by clone53421 · · Score: 1

      Nobody said anything about arbitrary bit flipping.

      The question is, can an algorithm be designed which runs much faster and gives a result within a desired tolerance of the correct result?

      To make a really horrid hypothetical example: Suppose you're designing an 8-bit multiplier. You know that you will be multiplying two large 8-bit numbers (in other words, you're not just dealing with numbers like 3 and 5 stored in 8-bit locations), and you can tolerate small errors in the multiplication as long as it's approximately right. Now, suppose your implementation would be very slightly faster if you assumed the lowest bit of each operand was 0. You'll get 113 x 87 = 9,632 (2% error), but in some cases it might be worth the time you saved.

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
    7. Re:What a waste of grant money... by gavron · · Score: 1
      Yes, it's always true that if you don't do the full calculation you can do it a lot quicker.

      The question becomes if we create a class of processing devices that are guaranteed to be less accurate (or if you like, they will be accurate "to a point") then we need to ensure that those are NEVER EVER used to
      a. Create other devices
      b. Check the accuracy of other devices
      c. Anything other than end-user consumer-grade large-tolerance-allowed use

      The question then becomes "How long will it be before someone uses these chips instead of regular chips because they are cheaper and faster..." and our entire technical infrastructure will go to heck.

      THIS is the reason why rulers are manufactured to tolerance. YES, they can make a lot more rulers if they don't measure them carefully and don't put all the little lines on them. HOWEVER by ensuring that ALL rulers are accurate, we [as a society] ensure that everything measured with them is accurate, and we can therefore extrapolate yardsticks, house framing, etc.

      I'm not on a rant. I understand we can do it faster and cheaper if we lop off a digit or two. I'm just saying if we allow inaccuracy we invite disaster.

      E

    8. Re:What a waste of grant money... by clone53421 · · Score: 1

      The question becomes if we create a class of processing devices that are guaranteed to be less accurate (or if you like, they will be accurate "to a point") then we need to ensure that those are NEVER EVER used to...

      Ok, point taken. There are plenty of applications where this sort of thing could be used, though — I think it's a fairly logical extension of the idea of discarding information in favour of added speed (usually transmission time over slow communications links) — we do it all the time in software. We're just accustomed to hardware costing a lot, which means we can't afford separate "accurate" and "fast" processors, which means we want the "accurate" one of course.

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
  28. No Ponzi scheme by Anonymous Coward · · Score: 0

    That's actually what Ponzi and his descendents tried to do. It was just little imperfections with 0s and 1s: a little accuracy sacrificed for the quantity of clients. You can't blame them, it's the progress damn it!

  29. where art and science meet, perhaps? by untorqued · · Score: 1

    This reminds me of the introduction to Samuel R. Delany's The Motion of Light in Water, where he talks about his admittedly faulty memory colliding with a biographer's researched facts. He concludes a long explanation with "...the wrong sentence still feels to me righter than the right one."

    No, this technology isn't appropriate for financial transactions. But anywhere that randomness could open the door to unexpected results that shed new light on something, I think this could be pretty exciting.

    1. Re:where art and science meet, perhaps? by gavron · · Score: 1
      Art has nothing to do with science.

      Science is the application of the scientific method.

      > I think this could be pretty exciting

      Pick up a Magic 8-ball or a pair of dice or do numerology on the next /. post following this one. Those are all equally random, and by your definition, exciting.

      Excitement should not come from "OH MY GOD WE'RE ALL GOING TO DIE" but rather from something positive. I don't want my planes, trains, automobiles, bank balances, MP3 players, GPS receiver, microwave, timed lights, alarm system, fuel-injection computer, television, DVR, or anything else providing me with extra excitement. I want them all to do EXACTLY what their specs say they will do.

      E

    2. Re:where art and science meet, perhaps? by osu-neko · · Score: 1

      I don't want my planes, trains, automobiles, bank balances, MP3 players, GPS receiver, microwave, timed lights, alarm system, fuel-injection computer, television, DVR, or anything else providing me with extra excitement. I want them all to do EXACTLY what their specs say they will do.

      At least half of the devices you mentioned do exactly what their specs say they will do inaccurately. They could do exactly what their specs say they will do deterministically inaccurately, or nondeterministically inaccurately much faster while using less power. Your eyes and ears will not notice the fact that the inaccuracies you're not really seeing and hearing are nondeterministic rather than deterministic.

      --
      "Convictions are more dangerous enemies of truth than lies."
  30. 19 times out of 20 by RichMan · · Score: 1

    Don't forget the probability is curve. You can design it so most of the time the lost accuracy will be where you don't care about it (the cents). But if a million people are banking, then probability says some of them will have significant errors (in the thousands column).

    This is not good for
    a) firing a missile
    b) driving a car
    c) designing a bridge or building
    d) my bank balance

    General computing.

    1. Re:19 times out of 20 by gavron · · Score: 1
      There is no bank which will run a system where 1/20 times they will have a 50% chance of losing money.

      Remember, it's not about the "probability curve" but rather that there are two sides to every equation. If you, THE USER, are willing to accept the chance of an error in your favor or against you, that doesn't mean THE OTHER SIDE will. Banks have to be accurate.

      Let's use another example, that fabled MP3 player where SOMEHOW MAGICALLY the processor knows whether it's being asked to decode an MPEG 1 Layer 3 frame Vs. it's being asked to calculate the next frame to retrieve. (There's no way for it to know.) So let's say that you're willing to accept an erroneous decoding of that frame. Ok. Perhaps the next frame also will be erroneously decoded. After all, it's like dice, EACH roll has that probablistic potential of being wrong.

      The artist who recorded the work, the producer who put it on the medium, and the distributor who sold it to you -- all of them DON'T WANT that lack of probablistic potential to degrade their work.

      So let's go from the other direction... WHICH APPLICATION wouldn't mind if it randomly did random things. You know, a simple IF-THEN will evaluate wrong, or a simple GOTO will go to somewhere else (or not go to at all) or a WHILE...DO will quit before being done...

      I have no idea which application (either software or real life institution) would go for this.

      E

    2. Re:19 times out of 20 by ChienAndalu · · Score: 1

      So let's go from the other direction... WHICH APPLICATION wouldn't mind if it randomly did random things. You know, a simple IF-THEN will evaluate wrong, or a simple GOTO will go to somewhere else (or not go to at all) or a WHILE...DO will quit before being done...

      I have no idea which application (either software or real life institution) would go for this.

      There are different kinds of instructions. Even today, floating point operations are done in a different area than jumping instructions like IFs and GOTOs.

      You can imagine a faster or cheaper chip that requires less energy that does floating point operations with 99% accuracy - or maybe even with an accuracy of your choice. So in your example, the code part that decides what frame to encode runs on the 100% accurate chip, the code part that creates the waveform or whatever runs on the chip with 99% accuracy. My ear probably couldn't tell a perfect waveform form a slightly different one.

      Or think about the brightness or color in a video clip - if the errors are small enough, it will just look like film grain.

      In video games, approximations are already being used, because you probably don't care if your rocket is flying with 10 units per second or 9.996 units per second.

    3. Re:19 times out of 20 by Anonymous Coward · · Score: 0

      I don't think computers work the way you think they do--Or engineering for that matter. I program--and I admittedly like to believe that my results are accurate because I wrote the algorithm correctly. Hopefully my ECC fixes a problem otherwise... But it doesn't change the fact that I'm working on an analog platform underneath things (call it digital--it's still low and high voltage)--built on a system with tolerances, percentiles of error, and some sort of bounded probability of failure in transistors. "It's complicated" is an understatement I hardly begin to understand. The bottom line is --even memory has a chance of just having a bit flipped (cosmic radiation changing computation is not a myth). *Everything* works within tolerances except for some places in mathematics.

      If I assume a 2^{-128} chance of a a computation getting impacted by some stray radiation--I need only run this computation 30 times if it's "wrong" 19/20 times to be more confident that my math is correct than I am that stray radiation has flipped a bit. Of course--that would obviate the power savings--more than likely the chip in question is a lower error rate than that. This would of course take three times longer--but one thing probabalistic methods lend themselves towards very well is *massive* parallelization. I could easily run this on 30 distinct chips and *still* be done in say...1/5 the time (some overhead for result aggregation in a fast VLSI)

      I can't find anything on the chance of cosmic radiation flipping a random bit on google right now...but these problems are actually particularly well known in some of the HPC fields (and not just because of 'compromises' in chipsets)--you do enough number crunching--problems happen sooner or later with a defective something. Assuming these can be quantified by a correctly engineered chipset--it may very well be completely reasonable to have a chip that is wrong as much as 51% of the time as long as it's sufficiently fast, cheap, and you have enough spee/throughputd to push them into a suitable voting system where you can bound the probabilities. That would require an architectural change right now... but your "19/20" example actually seems completely feasible to me at first glance even using basic iterative methodologies.

      (Yeah--I wouldn't want to be the one to explain how it works to a customer who doesn't get probability...)

      So yeah--any application in real life could use this.

    4. Re:19 times out of 20 by sketerpot · · Score: 1

      That's why these guys want to make systems-on-a-chip which integrate probabilistic circuitry with an ordinary ARM processor core. It can handle the general computing and the probabilistic coprocessor can handle a few specialized jobs. This won't replace your CPU, but it might make your graphics card faster and more efficient a few years from now.

  31. The first thing that comes to mind... by Lordfly · · Score: 3, Insightful

    ...is gaming applications.

    Programmers spend a lot of time coming up with algorithms that simulate randomness for AI or cloud generation or landscapes or whatever... if the processor was just wonky to begin with it'd make certain things a lot more natural looking.

    It's interesting that AI in games is always touted as being "ultra-realistic", but always ends up being insanely easy to trip up. Having something "close enough" would add just enough realism/randomness to situations to perhaps make games and environment more dynamic.

    I wouldn't want these things processing my bank balance, though, unless it rounded up.

    --
    hookers and grits.
    1. Re:The first thing that comes to mind... by Jiyunatori · · Score: 1

      The first thing that comes to my mind is my field of research : "numerical" artificial intelligence (as opposed to symbolic AI).

      When you run artifical neural networks, you usually do it to process noisy, real-life data. In such a case, you just don't give a damn about precision : this is just a bit more noise, and your processing paradigm is studied to tackle with noise.

      Right now, we are definitely missing horsepower in this field. With a state of the art computer you can only hope to do very basic stuff in realtime. Unless you have a lot of money, you are stuck.

      Such a technology could be a gift for us. ANN need raw computing power, probabilistic chips need noise tolerant computing - it could be a perfect match.

      I'm already having wet dreams of PCIe cards with a few GB of fast access RAM and a massive number-crunching probabilistic CPU ...

    2. Re:The first thing that comes to mind... by LordKaT · · Score: 1

      You know, if you put "wonky processor" in the same area as "modern game AI" you're going to end up with CoD soldiers that end up blowing their own heads off because they walked into a wall.

    3. Re:The first thing that comes to mind... by sketerpot · · Score: 1

      You're exactly right and should be modded up to 5. One of the applications that these researchers keep trotting out in their papers is neural networks. They figure they can make neural network hardware a few hundred times faster or more energy-efficient, as compared with a non-probabilistic CMOS implementation. They're also looking at Bayesian inference and classification problems, so that's nice too.

    4. Re:The first thing that comes to mind... by Jiyunatori · · Score: 1

      If only I could be modded up to eleven ...

    5. Re:The first thing that comes to mind... by Anonymous Coward · · Score: 0

      According to the article,

      "All of this worked well enough in mathematical theory and simulations, but Palem couldnâ(TM)t prove his concept until he built and tested a chip. The first test results came back late last year.

      All of this worked well enough in mathematical theory and simulations, but Palem couldnâ(TM)t prove his concept until he built and tested a chip. The first test results came back late last year.

      âoeAt first, I almost couldnâ(TM)t believe them,â he said. âoeI spent several sleepless nights verifying the results.â"

      So apparently this thing is being used in web publishing, as well.

    6. Re:The first thing that comes to mind... by Tom · · Score: 1

      Errr... no?

      What you're looking for in games is not randomness - that's easy to come by, just fetch it from /dev/urandom.

      The whole point, for example, in landscape generation is not that your computer is "too precise" or anything like that. It's the simple fact that natural shapes are nowhere near random. Getting a landscape from a random data generator will yield you anything, but not a realistically looking landscape.

      Likewise, the problem with AI is not that it is "too exact". It's trivial to add some random spread to the shoots, or some randomness to the position evaluation or decision tree. The point, again, is that natural behaviour of men or animals might look like random at first glance, but the same eye/brain combo that tell you "random movement of people" when you look at a video of a shopping center, will immediately alert you that something is very wrong when those people actually do move randomly.

      That's because the common-sense definition of "random" isn't the mathematical definition. When we say "random" in a normal environment, we mean "can't make a meaning out of it at once" or something like that. In fact, true randomness is very counter-intuitive. The simplest test I know is to ask people which sequence on a die roll is more likely, 3-5-2-1-4 or 6-6-6-6-6.

      --
      Assorted stuff I do sometimes: Lemuria.org
    7. Re:The first thing that comes to mind... by clone53421 · · Score: 1

      That's not randomness, that's just Unicode-to-Slashcode conversion.

      Oh wait.

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
  32. A Little Bit of History Repeating by lobiusmoop · · Score: 2, Interesting

    So basically he's advocating fuzzy logic, which was big in AI research in the 80's?

    --
    "I bless every day that I continue to live, for every day is pure profit."
    1. Re:A Little Bit of History Repeating by Jay+L · · Score: 1

      That was my first reaction too - and, by odd coincidence, that just popped into my head last night. "Hey, whatever happened to fuzzy logic?"

      From what I remember, the practical applications all boiled down to one technique: lookup tables. Washing machines would eliminate the need to set temperature, spin speed, etc. separately. You'd tell it what fabric and what type of soil, and it would use fuzzy logic to determine the best laundry parameters. AFAICT, that's just a lookup table - with maybe some precursor to Bayesian stuff. There was even a slogan in Japan: "It's fuzzy!" (Yes, we know.)

      But as TFA and some commenters pointed out: this could be great for streaming media, or anything else that doesn't need a precise answer. With things like OpenGL, what if you kicked off a few threads that explicitly didn't need precision? You'd have a fuzzy coprocessor, just like graphics and math and crypto coprocessors.

      I wonder: are the failure modes predictable enough that you could wrap calculations with middleware, which would repeat them enough times to reach your desired level of accuracy (thus losing only precision, not accuracy)? If the failures are randomly distributed, and you can overclock things 7x, you could run everything 3x and still come out ahead.

    2. Re:A Little Bit of History Repeating by osu-neko · · Score: 3, Insightful

      Sorry, I missed the part back in the 80's where using fuzzy logic caused my processor to consume 1/30th the power.

      --
      "Convictions are more dangerous enemies of truth than lies."
    3. Re:A Little Bit of History Repeating by BotnetZombie · · Score: 1

      The Monte Carlo method was what I thought of when RTFS. In the wikipedia article there's for example a neat way to calculate pi with whatever precision you want. And as a little anecdote, I used this method once for a board game in a school project. It beat the hell out of some minimax variants.

    4. Re:A Little Bit of History Repeating by anonymShit · · Score: 1

      maybe because back then it was software-level. Now it's hardware level (your fuzzy probability number is not stored in the hardware like 0.8000000000000, but 0.8)

    5. Re:A Little Bit of History Repeating by DwySteve · · Score: 2, Informative

      This is not fuzzy logic. In fuzzy logic 'fuzzy' applies to the 'logic' of the decision-making process (ie, not binary TRUE or FALSE, but 'fuzzy' - somewhere in between). This and this are fuzzy logic.

      Basically he uses probability, fuzzy logic uses certainty. It's a hard distinction unless you really like math but if you want to argue it's worth arguing.

      --
      http://angryee.blogspot.com
  33. Well, it's a *little* more important by roystgnr · · Score: 2, Interesting

    For example, in calculating a bank balance of $13,000.81, deliberately risking getting the "13" incorrect is fraud that risks $13,000 in damages and $1,000,000 in statutory penalties, and risking getting the "81" incorrect is fraud that only risks $0.81 in damages and $1,000,000 in statutory penalties. Surely saving a couple watt-microseconds is worth that!

    1. Re:Well, it's a *little* more important by Anonymous Coward · · Score: 0

      At least read the article. That was just a bad example they gave.

    2. Re:Well, it's a *little* more important by Anonymous Coward · · Score: 0

      Watt-microseconds is not canon SI. Please just say mJ for milli Joules or something like that!

  34. Financial transactions aside... by suffix+tree+monkey · · Score: 1

    ...it would definitely make some games more fun. Imagine that at the end of the game, you meet the big boss - but instead of his usual self (object 13023), he looks like the one at 13024, a steel door.

    1. Re:Financial transactions aside... by Shadow+of+Eternity · · Score: 1

      Given the current state of difficulty settings and boss AI I'm not entirely sure players would notice the difference.

      --
      A bullet may have your name on it but splash damage is addressed "To whom it may concern."
  35. wrong target by 800DeadCCs · · Score: 1

    Anyone who used this for money would (and should) be skinned alive.
    It's the wrong thing to target.

    If it's not exactly accurate, but instead centers around averages, (how well does it converge towards the REAL answer?) then I could see uses for it, but still in parallell with normal procs for a rough "checksum"...

    CGI and various modelings where you just need to pour power at it for example.

    Maybe make some kind of "accelerator" board with it to be used for certain apps.
    (Still pissed about not having a reasonably priced cell board like that).

  36. GREAT! fresh bugs by Anonymous Coward · · Score: 0

    all we need is a fresh bunch of hardware bugs in our computing society, and just when we got to killing some of them from our software.

  37. Cher Patent Term Extension Act by tepples · · Score: 1

    I guess the question is can Cher sue over this technology?

    Only if lawmakers pass the Cher Patent Term Extension Act.

  38. Re:It seems like when you need a precise calculati by phoenix321 · · Score: 1

    Repeating the process is not going to improve the results.

    Suppose you repeat your calculation 3 times. How will you know that the result of comparing the three results with one another is correct?

    What if the only answer you can obtain is "A equals B with a probability of 0.9998"? Recursively repeat this comparison and then compare the results? :)

  39. I finally understand by BubbaDoom · · Score: 1

    The answer 42 now makes perfect sense.

  40. hopeless article by kwikrick · · Score: 1

    No information in TFA whatsoever, only a rather bad example.

    Probabilistic algorithms are very useful in computer science, and introducing uncertainly at the hardware level might be very interesting for some applications. But how did they implemented this? How do they save power? How are they faster than normal processors?

    Bah. I hate non articles like this.

         

    --
    assignment != equality != identity
    1. Re:hopeless article by Asic+Eng · · Score: 1
      There doesn't seem to be much information out there. The professor exists though: http://www.cs.rice.edu/~kvp1/ . He also has a paper available on "probabilistic boolean logic" http://www.cs.rice.edu/~kvp1/probabilisticboolean.pdf . However that doesn't explain any technology benefits which would give an insight how he wants to trade accuracy for speed or power.

      I suppose the simple way would be to just reduce core voltage and violate setup times. Similar to overclocking this would in many cases work without noticeable errors. I found an article which would indicate that he's indeed looking in that direction: http://legerdemain.wordpress.com/2008/03/08/the-probabilistic-chipsa-heresy "Palem's idea is to lower the operating voltage of parts of a chip-specifically, the logic circuits that calculate the least significant bits"

      So that would mean he's using less power for some parts of the chip, where he doesn't need so much accuracy, but providing normal power to other parts.

      Interesting concept, but as a chip designer my suspicion is that this will never leave the prototype stage. There have been many ideas like this one before, and there are a few hard barriers which they usually can not overcome: design for test/yield, designflow and competing evolutionary approaches:

      Design for Test (DFT) means he'll need to figure out how to automatically generate tests which can identify broken chips. This is a well-understood problem currently, but the "low power areas" of his chips will introduce unknown values to the "high power areas". This means the test coverage will sink, and this in turn means: more defect chips will be identified as operating correctly. (Not operating correctly in the areas in which he needs accuracy, that is.) He might be able to solve this by using more complex more adaptable tests running on better testing hardware - however that means increased test cost, and test cost is a big factor in overall manufacturing costs.

      Designflow means he'll need to develop tools which can handle the additional complexity during device development. For example verification is one of the biggest factors in development. Now if you introduce more variability into some parts of the device, then you need to run more tests to investigate how the different outcomes of the "low accuracy areas" effect the "high accuracy areas". With standard digital design you have just one outcome for a digital block - now if you have e.g. 20 different outcomes that could potentially mean you need to run the same test 20 times - one for each result. More time spend in simulation essentially means longer time to market - again a very critical issue.

      Competing evolutionary approaches - there are a lot of them already in use. One approach is to just clock-gate certain parts of a chip, or (if leakage is too high) you can even turn-off the power to some parts of the chip. You might just have a part of the device running which checks occasionally if the rest of the device is needed and activates it on demand. (See Freescale's MPC560xS for an example.) You could also just pick a less accurate algorithm for your "fuzzy" tasks (silly example: using 3 decimal points rather than 8 - you could even calculate in advance how much your error could be - less digital logic means less power consumption, too.)

      Now having said all that - he may very well find solutions for all these problems and I wish him luck. I just wanted to give an idea of the obstacles he needs to overcome. However so far he just has a prototype - as counter-intuitive this may sound: that's the easy part. Getting to this stage means he has 20% of the problems solved. That's great, but if we hear from this again it will be in a few years at the earliest.

  41. Or maybe we could... by PaulBu · · Score: 2

    Maybe we could have a selective accuracy, where programmers can set their needs via registers or direct it to different CPU cores ... just keep using (say, in C) short, int, long, long long (no, AV codecs should not require floating point, but is you wish, there are floats, doubles, long doubles, etc.).

    Of course proper implementation of some AV decoder on a modern processor will use available SIMD instructions (MMX and friends) where programmer can easily trade off accuracy (in byte-sized chunks) for speed.

    Paul B.

  42. Hell, they kind of already do this by NotSoHeavyD3 · · Score: 1

    I mean a float isn't an exact number. (Actually they have that concept in the hard sciences as well called significant figures. To give an analogy that's based on a joke if a museum guard started working in a science museum 15 years ago and there was a fossil there that was 80 million years old when he started the fossil is not 80,000,015 years old.)

    --
    Did you know 80 to 90% of the moderators on slashdot wouldn't recognize a troll even if one dragged them under a bridge.
  43. So, to get it right... by Presence1 · · Score: 1

    ... they would need to use a crowd of these processors and some kind of "wisdom of crowds" algorithm to figure out which of the output values is good.

    So, in rough figures, if 30 processors is enough to get a good reliable answer from the 'crowd' of procesors, and the overhead of the "wisdom of crowds" algorithm is less than 14%, then maybe we have a system that uses the same power and is about 6x as fast, but no power savings.

    If a less good answer is acceptible, then maybe only a few processors are necessary, and there is a net power savings. If it takes more than a crowd of 30 to make a completely reliable answer, then it costs power, but we still get a faster system.

    It could be useful for certain applications, if carefully applied. In addition to the media playback and gaming apps already mentioned, it could be good in robotics, where speed amd low power count for a lot, and the feedback loops do a lot of successive approximation anyway.

    1. Re:So, to get it right... by osu-neko · · Score: 1

      ... they would need to use a crowd of these processors and some kind of "wisdom of crowds" algorithm to figure out which of the output values is good.

      No. They would use one processor and accept the result. If you're trying to cobble together a "wisdom of crowds" solution, you've completely missed the point. If one of these processors isn't good enough, you're using the wrong kind of processor -- you need the kind designed for accuracy instead.

      --
      "Convictions are more dangerous enemies of truth than lies."
    2. Re:So, to get it right... by Presence1 · · Score: 1

      Good point, but I don't think it is quite that binary.

      The 'wisdom of crowds' solution is already used in very critical situations, with processors designed for accuracy; e.g., the Space Shuttle has 5 separate computer systems, and accept a majority result from the primary 4, or use the 5th as a tiebreaker if the primary 4 are split.

      If you abolutely NEED more speed than the 'accurate' processors can be provide, and one of these 'inaccurate' processors is insufficiently accurate, then a crowd could improve their accuracy enough to be useful, and still provide the speed you need.

      So, while crowd configurations would probably not be the most commonly deployed design, it isn't a completely unreasonable design approach.

  44. Porn? by gravis777 · · Score: 1

    Yeah, cause no one will care if you try to log into godtube and instead get horse-on-girl porn

    Or, because the suffix is unimportant, I get whitehouse.com instead of whitehouse.gov

    Cause you all know I must have a processor 7 times faster than what is in an iPhone or blackberry to watch video streaming over 3g on a 2 inch screen

    The lower power consumption might be a plus, though

    1. Re:Porn? by Anonymous Coward · · Score: 0

      Yeah, cause they're talking about replacing every CPU in every computer with one of these

      Or, because every programmer on Earth will be too stupid to use the right processor for the right application

      Cause you all know that once we have lossy 640x480 video in our hands we can stop the drive for better technology

  45. Welcome to Bizarro World by Anonymous Coward · · Score: 0

    I don't know if the Professor or the reporter wrote the example, but they must inhabit some alternate bizarro world.

    I know that if my bank account was supposed to be $13,000.81 but my bank came up with $13,000.57 instead, I'd be massively upset.

    Moral: Always pick a reasonable analogy to describe your new idea, otherwise you'll get thrown in with all the other crackpots with idiot ideas.

    1. Re:Welcome to Bizarro World by osu-neko · · Score: 1

      As an example of how some bit-flips make a bigger difference than others (which is what it's supposed to be an example of), it's a great example.

      As an example of an application where it makes sense to use this kind of processor, it would be a lousy example, but that's not what it was supposed to be an example of anyhow.

      Moral: No matter how reasonable your analogy, some people with poor reading comprehension skills will think you're an idiot because they can't read very well. Don't worry about it, it's unavoidable, just carry on...

      --
      "Convictions are more dangerous enemies of truth than lies."
  46. for simulation by kilraid · · Score: 2, Insightful

    For simulation, Monte Carlo and such statistical sampling this would be perfect. There is already random error - sampling error - so adding a lesser source of error - computational error - while reducing the first would make sense if the computations can be sped up.

  47. It makes sense to me by Anonymous Coward · · Score: 0

    All processors have errors and systematics. Just perform complicated calculation in two computers and the results won't be identical, although statistically very similar.

    However, there is no word in the article about how faulty the "new" processor is. He says that it would consume 1/30th of power and be 7 times faster. Let's go for probabilistic computing! Put 30 processors and gain 210 times in speed, make the calculations in each processor and make statistics.

    It doesn't seem to me a bad approach.

  48. Obligatory NASA research by DirePickle · · Score: 5, Funny
    From NASA:

    Computer scientist Arthur Boran was ecstatic. A few minutes earlier, he had programmed a basic mathematical problem into his prototypical Akron I computer. His request was simply, "Give me the sum of every odd number between zero and ten." The computer's quick answer, 157, was unexpected, to say the least. With growing excitement, Boran requested an explanation of the computer's reasoning. The printout read as follows: THE TERM "ODD NUMBER" IS AMBIGUOUS. I THEREFORE CHOOSE TO INTERPRET IT AS MEANING "A NUMBER THAT IS FUNNY LOOKING." USING MY AESTHETIC JUDGEMENT, I PICKED THE NUMBERS 3, 8, AND 147, ADDED THEM UP, AND GOT 157.

    A few moments later there was an addendum: I GUESS I MEANT 158.

    Followed shortly thereafter by: 147 IS MORE THAN 10, ISN'T IT? SORRY.

  49. Look, it's probability theory... by mosel-saar-ruwer · · Score: 1


    Suppose you repeat your calculation 3 times...

    If you get three different answers, then you just take the average.

    You could even throw in a few extra circuits to throw out wildly anomalous values.

    In fact, you could change your computer circuitry from ADD(X, Y) to something like ADD(X, Y, SD), where SD is your [hypothesized] standard deviation, and any cluster of values which appear to be generating an unacceptable standard deviation would get tossed.

    1. Re:Look, it's probability theory... by Falstius · · Score: 1

      That is so 1960s. Modern error correction algorithms are much more efficient. If the machine runs 7x faster and you use an error correcting algorithm that uses 2x as many ops you're still 3x ahead. And you could selectively apply the error correction depending on where you needd more or less accurracy. Even for financial applications, there is an upper bound to the accuracy required.

    2. Re:Look, it's probability theory... by Anonymous Coward · · Score: 0

      You can only benefit from error correction/checking that if you can somehow verify the result. Say like when you unzip, you can verify the CRC.

    3. Re:Look, it's probability theory... by Falstius · · Score: 1

      You can verify the result. If you're familiar with some basic communication theory, consider one of the operands as the source, encode it with some redundancy (parity bits for instance), and pass it through the channel which is the 'probabilistic' processor and the other operand. The channel parameters will give you a probability model for the output which you can use to try to correct any errors that occurred. This situation is very similar to a regular communications system, except there you don't even know the original signal (if you did, you wouldn't need to communicate it).

  50. Article devoid of content by Anonymous Coward · · Score: 0

    This article doesn't in any way explain this concept. Seems like it may potentially have merit, but no detail is given as to the implementation. The IEEE floating point representations already trade off accuracy for speed/efficiency. So, surely that isn't what is being claimed.

    The article implies that noise in some bits is more significant than in others and that this leads to increased energy expenditure, but doesn't explain how this is leveraged.

    Does the proposed processor perhaps ensure high precision for high-order bits, and less precision for low-order bits in multiplications and additions, say? That leaves a lot of open questions for other kinds of instructions.

    Obviously, that approach wouldn't work for the vast majority of existing control systems in software, which require binary answers, but it might be compatible with a looser logic system like fuzzy logic. That requires supporting infrastructure that isn't mentioned, however.

    It's possible the errors are rare or correctable, as has been developed in quantum computing, but this point isn't developed either.

    It's also possible, as in one earlier comment I read that this is some form of variable-precision, but that would need some explaining as well.

  51. Have Both With Ninnle! by Anonymous Coward · · Score: 0

    The legions of Ninnle Linux users can tell you that, with Ninnle Linux, you can have your cake and eat it too. Speed, accuracy, flexibility and security all in one package. Join the Ninnle Revolution today!

  52. Re:It seems like when you need a precise calculati by Anonymous Coward · · Score: 0

    like financial things, you compare the end product with the end product of the same calculation run either through the chip again or another chip (or increasingly likely another core).

    There's nothing saying the probabilities are independent of each other. It's possible that identical calculations will result in the same wrong answer multiple times, instead of a range of wrong answers.

  53. Just use analog computing by joekrahn · · Score: 0

    Why use a very complex system to make digital computing behave like analog computing?? It would be better just to have part of the chip or a co-processor run using analog signals. With analog, you can probably increase the clock speed and increase the noise level rather than getting intermittent total failures.

    But, given that all of the analog devices are going digital, there are probably not many useful applications.

  54. entirely off-topic, but... by gadabyte · · Score: 0, Offtopic

    while i agree with you about the audible difference between lossy and lossless formats on a portable music player, the palatable difference between tap water, well water, and spring water (from the source, not bottled supposed-spring water) is huge.

    i work in designated wilderness areas, and there is nothing like the taste of water that you can see coming out of the ground. even from spring to spring the taste varies greatly.

    the best water in the world comes from the spring at tom taylor cabin, in the marble mountain wilderness, klamath national forest.

    --
    the united states is a nation of laws; badly written and randomly enforced -- frank zappa
  55. This reminds me of the OS X Finder. by Anonymous Coward · · Score: 0

    With the OS X Finder, they rationalized that polling wasted cpu cycles so they avoided it at the cost of displaying incorrect information about directory contents when changes were made in the background.

    The morons didn't realize that getting inaccurate information 1% of the time made the Finder unreliable 100% of the time.

  56. This is the chip Lehman Brothers rely on. by Anonymous Coward · · Score: 0

    nt

  57. Instruction-level implementation seems more correc by CarpetShark · · Score: 1

    Didn't Intel already implement this technology in their Pentium 2 FPUs? Didn't seem very desirable to me...

    I assume this is a joke referring to pentium bugs, but actually, I think instruction-level implementations WOULD be (and is) the desirable place for this. Essentially we're just talking about hardware RNGs and fuzzy calculations. As I understand it, this is widely available already. The problem with doing this CPU-wide is that, as others have pointed out, we DO need accuracy most of the time. Processors are all about executing algorithms. We need algorithms to be predictable. Some algorithms are lossy, yes, but the algorithm itself is predictable. The best example (I know of) is probably genetic algorithms, where all of the "lifeforms" are largely random and most can be WAY off the desired outcome, but the testing system MUST be accurate. So essentially what you need is a clearly lossless execution system, with only a few instructions using randomness. Which is what we have now, including hardware-assisted randomness in some cases. Aside from that, the only lossy testing I can see a use for is things like not checking the least significant bits of a real number when the most significant bits are clearly wrong. That's essentially a lossy test, but it's also just a well-known optimisation technique.

  58. Reminds me of an old loke by mariuszbi · · Score: 1

    Q:How do you call the Intel Pentium FDIV instruction? A:A good random number generator!

  59. The Ultimate Answer by olivier69 · · Score: 1

    41.9

  60. Bad example... by Firethorn · · Score: 3, Insightful

    It looks like you got sucked into the bad example land. Later on in the article it mentions that it's intended for stuff where accuracy isn't paramount, but where it's not really necessary. Multimedia applications over space/bank calculations.

    I mean, there's 1.764 Million pixels in my screen that I'm typing my post on at the moment. Does it really introduce much error if I round it to 1.8M? I'm also running at 60Hz. Do you think that I'd really notice if there's a .01% chance that instead of getting white(255) I get white(254)? That'd be an average of 176 pixels a refresh, assuming an all-white screen. Thing is, those pixels wouldn't be the same every time. Then again, logically each pixel would tend towards red/blue/yellow depending on the error. But only slightly. In a HD movie, are you really going to notice?

    --
    I don't read AC A human right
    1. Re:Bad example... by osu-neko · · Score: 1

      It looks like you got sucked into the bad example land.

      Actually, it's a great example of how certain parts of a result are more important than others. If you mistakenly thought it was an example of a good application for this sort of thing, it would seem like a bad example, but that would be due to the error in reading comprehension, not in the example. The average person doesn't know how digital music is encoded, but they understand dollars and cents. If you're trying to explain why some bits flipped make more difference than others, this is a great example for a general audience.

      --
      "Convictions are more dangerous enemies of truth than lies."
    2. Re:Bad example... by Firethorn · · Score: 1

      I guess the example as a good point to general audiences like, perhaps, my parents. I certainly got what they were after.

      Many slashdotters seem to take things too seriously though. They take the bank example as serious.

      --
      I don't read AC A human right
    3. Re:Bad example... by ai4px · · Score: 1

      To accept this premise we must accept that a bit error could occur anywhere.. but we as humans tend to accept LSB errors and pretend that MSB errors won't happen.

      White as 255 or white as 254 sure, who would care... but the hardware noise could introduce an error at ANY bit... How do you feel about white as 127?

    4. Re:Bad example... by Firethorn · · Score: 1

      Bit errors can occur anywhere NOW. They're just very unlikely.

      Besides, the whole premise of this article is some methodology to keep MSB error rates the same while sacrificing LSB accuracy in exchange for more speed, lower power, and cost...

      I mean, how much silicon is used to ensure that errors are detected and corrected? How much space, power, and speed is sacrificed for the circuitry required to make sure the LSB is correct?

      --
      I don't read AC A human right
    5. Re:Bad example... by ACMENEWSLLC · · Score: 1

      Ok, so when I divide 1/9 I get 0.11111111111111111111111111111111.

      In my program I am taking the result and formatting it as .11, as that is all my calculation needs to go out to.

      So what if instead of wasting time computing and keeping track of the calculation all the way out, I could tell the computer to just come close - show me out to the hundreds?

      I think this is maybe a better example?

    6. Re:Bad example... by Firethorn · · Score: 1

      So what if instead of wasting time computing and keeping track of the calculation all the way out, I could tell the computer to just come close - show me out to the hundreds?

      I think this is maybe a better example?

      Not exactly...

      Think about color - 8 bit color is only sufficient to show artificial images, since it can only show 256 colors at a time. 16 bit is a LOT better, but you can still see problems with photos as the human eye can still see more than 65.5k colors. The 16 Million of 24 bit color satisfies most eyes, but most imaging is done in the 4 billion possible color/brightness combinations of 32 bit to limit the loss of fidelity due to rounding.

      Anyways, when you're doing image arrays, the least significant digits don't make much difference each, but you can't get rid of them entirely and still maintain image quality. Noise over loss of signal, essentially. We'd rather have the 'noise' of lossy compression over sacrificing resolution or color depth. Actual studies comparing various compression schemes vs reducing resolution to get the same image size has shown this before.

      Remember - I'm figuring that the system will fail to compute the exact value less than 1% of the time. I'm also not saying the data, even out to the LSD, isn't valuable, it's just less valuable than the MSD.

      It's more like computing 1/9 and getting .1111111111112, and calling it 'good enough', cause, well, we have 4 billion OTHER pixels to calculate and we can't dawdle. Besides, we'll be doing all of this again in 1/60th of a second anyways.

      It's like doing an audit back in the days of paper and calling the result 'good enough' because it's only off by $1.21 out of 2 million. It's not worth the effort to track down the effort. The people jamming data into early calculators pay more attention to the starting digits than the ending ones when adding/subtracting, etc...

      --
      I don't read AC A human right
  61. Another Toy - by Anonymous Coward · · Score: 0

    Sounds like just another toy.

    We could couple this with everyone's favorite toy programming language 'java'.

    java floating point was never IEEE correct anyway, so it would be a perfect match.

    I don't see why people programming in a toy programming language should need expensive modern processors. It's FREE anyway, so why not use an inexpensive, inaccurate chip.

    We could literally give computers based on this chip away, and include a little java interpreter. It would let kids enjoy the joy of programming, without having to worry about the 'hard stuff' since java would take care of it.

  62. There is a difference between random and precision by Anonymous Coward · · Score: 0

    This guy just found out what has been known for a long time : some calculation and processing support approximation better than others (remember the difference between using simple precision, double or quadruple ?), and you want to have your error on the lowest significant digit. Gee. So what now ? Implement a FPU with single-precision, double and quadruple , to lower the energy cost ?

  63. 9000 by nuclearrrabit · · Score: 1

    It's somewhere in the vicinity of 9000!

  64. Teacher says... by jcwayne · · Score: 1

    As long as little Johnny feels good about himself it's okay if he thinks 2 + 2 = 5. In the real world he'll have computers and calculators to depend on for math anyway.

    -National Education Association Handbook

    --
    Failure to follow this advice may result in non-deterministic behavior.
  65. This is already being done in Quake 3 by siDDis · · Score: 1

    For some years ago Slashdot had a news article about this http://www.beyond3d.com/content/articles/8/

    1. Re:This is already being done in Quake 3 by osu-neko · · Score: 1

      Really? Already done in Quake 3? I missed the part about Quake 3 causing my computer's energy usage to drop 97% while playing, and I'm afraid the article you linked to didn't really explain how Quake 3 achieved this.

      --
      "Convictions are more dangerous enemies of truth than lies."
    2. Re:This is already being done in Quake 3 by Anonymous Coward · · Score: 0

      Quake 3 almost don't use any energy to run, the game runs on cell phones today!

  66. Debugging nightmare! by SubaruStarship · · Score: 1

    I haven't read the article. However, the idea of this sort of processing technology finding its way into general purpose computers makes my skin crawl. Isn't there already enough uncertainty in computing? We already have spurious hardware malfunctions and uneasily reproduced software glitches to contend with. It's hard enough when troubleshooting issues to discriminate between the existing, overwhelmingly unintentional sources of computing errors without having to consider the possibility of intentionally sloppy chips.

    A number of people have voiced concern about using sloppy chips in the context of banking and finance. At least in those contexts you're dealing with data that's not obfuscated in any way--corporate financial statements aside. Consider what would happen if you attempted to compress or simply encode data with a sloppy processor. If you used any existing lossy algorithm the results would be worse than you'd expect, but still potentially within the realm of acceptability. If you used any existing lossless algorithm, the results would be useless. By including trustworthy error correction metadata you could perhaps overcome issue of data unreliability, but you'd have to perform additional calculations to correct the data, thus eating into the efficiency gain achieved by using a sloppy processor. The end result? Greater uncertainty of data correctness, greater complexity of design to overcome uncertainty, and greater difficulty debugging reported issues.

  67. Basic estimating by CarpetShark · · Score: 1

    Accuracy with financial calculations is extremely important.

    So is basic estimating, which helps you to come up with and verify an accurate answer sooner. That, and standard optimisation techniques based on it, are all this seems to be suggesting. I'm sure the professor isn't trying to claim a big innovation here. This is probably some rookie reporter out looking for a big story, and failing to realise that big stories take actual research, donkey work, and guts.

  68. Why not just lower the precision? by bobl · · Score: 1

    I'm not able to find Dr. Palem's original paper from the "computer science meeting in San Francisco," but if, as I surmise, he's advocating a new probabilistically-based microprocessor, the question needs to be asked: If we're willing to consider new architectures (and new ways to program them), is a probabilistic one the best solution to the power consumption and performance problems?

    One alternative that should be compared to Palem's would be to do the same thing he's advocating -- reduce the precision -- in a more traditional way: explicity reduce the size of the data path. Quite a few applications could get by with shorter-than-32-bit integers. If not 16, maybe 24? For floating point calculations, many GPUs already support a 16-bit "half" or "s10e5" format (IEEE 754 2008) that's just fine for multimedia. There's also a 24-bit format.

  69. not the same by imsabbel · · Score: 1

    There is a difference between an appoximation and the way the article want to have errors possible.

    The approximation used in quake 3 will give the same results everytime. It wont be the _exact_ result, but it will be reproducable.
    The same way things are done in the CPUs, anyway. They just run the newton-raphson loop a few times more to get a guranteed minimum accurace.
    But that doesnt mean its always the same (in the whitepapers of cpu manufacturer you can find really funky graphs, for example for the error of FSIN (X) for x[0...pi/4].

    With the approch from the article, the same calculation may return different results. That a nightmare in terms of error estimation and propagation, except in some very limit cases....

    --
    HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
    1. Re:not the same by gnasher719 · · Score: 1

      With the approch from the article, the same calculation may return different results. That a nightmare in terms of error estimation and propagation, except in some very limit cases....

      Actually, reproducible results may create the wrong impression that the results are actually meaningful. If a processor did random rounding, then you could run an algorithm twice and compare the results; if random rounding creates different results, then you know that reproducible rounding won't produce meaningful results.

  70. Watch out by PPH · · Score: 1

    The "Wisdom of Crowds" brought us religion. If microprocessors pick it up, we might end up with Our Lady of SkyNet.

    --
    Have gnu, will travel.
    1. Re:Watch out by Anonymous Coward · · Score: 0

      -->The Matrix-->odd things like Schrodinger's cat

  71. Your hearing megahurtz! by w0mprat · · Score: 1

    In portable media applications of this, you'd be literally hearing background noise from the processor rather than just from the lossy compression algorithm and the reproduction circuitry (notoriously big sources of noise).

    If they are talking about imprecision on average of parts per million then you'd never hear it. Even 1 to 10000 is still within the noise floor of your average ipod.

    The order of magnitude increase in computational performance could allow for improved compression algorithms with less destortion. The net result is this kind of thing has potential to vastly improve audio/video and battery life.

    --
    After logging in slashdot still does not take you back to the page you were on. It's been that way for 20 years.
  72. The devil is in the details... by tacarat · · Score: 1

    ... but God turns up unexpectedly.

    So how would this affect AI research? Is the occasional fried synapse what separates a "living" mind from that of a biological computer?

    --
    "Common sense will be the death of us all"
  73. What good is a processor that can not be verified? by mlwmohawk · · Score: 1

    Seriously, people have been talking about "fuzzy" processing for decades and it always fails for the same reason. It is not repeatable and it can not be verified.

    So, of what use is a processor for home or office that does not compute accurately. Music should sound the same each time you play the same "image.". Graphic images should look the same every time you view them. Checkbooks should balance, and don't use this device on turbo tax.

    How does one distinquish, during development, from a "bug" in the software being developed and just fuzziness?

    So, yes, it is fun to get computers to "guess," but you do need to understand where the guesses come from, and be able to repeat them.

  74. This is retarded ... why? by Anonymous Coward · · Score: 0

    The same ALU that computes your PCM audio also computes addresses and other info. You can't be "somewhat correct" in your address computation. And having redundant circuitry so your PCM data can be quickly [and inaccurately] generated is retarded.

    This might make more sense in dedicated units like GPUs where it's almost always outputting pixel data and rarely doing house keeping like addresses or manipulating data structures [like BSP trees, etc].

  75. Re:It seems like when you need a precise calculati by johanatan · · Score: 0

    Wouldn't it need to be 2 others as in 'minority report'?

  76. Obligatory by Anonymous Coward · · Score: 0

    Great! Now we finally have an architecture on which to build a probability drive!!! The next generation space shuttle will be able to get to any random place in or out of the universe instantly.

  77. Re:It seems like when you need a precise calculati by Tuoqui · · Score: 1

    I imagine if both cores come up with the same result that the odds are high its a correct result (not very likely both runs will come up with the very same wrong answer). If one or the other is wrong then you toss the result and re-request until you get an agreement between the two cores.

    Naturally this only works if the 'error rate' isn't ridiculously high like 50% of all things passed through it. If its more like 1% of everything passed through it comes up in error and you double up all your calculations (using cores that use 1/30th the electricity) you might still come out on top in terms of energy usage (assuming you were using 2 cores to do your math in the first place).

    --
    09F911029D74E35BD84156C5635688C0
    +2 Troll is Slashdot's way of saying groupthink is confused
  78. Good idea, TERRIBLE TERRIBLE TERRIBLE example by Anonymous Coward · · Score: 0

    This guy has just lost forever the financial industry as potential customers.

  79. Redundancy by Al+Al+Cool+J · · Score: 1

    I wonder if there is some efficient way of putting in three or more chips, running all calculations repeated in parallel, and apply majority-rule to the result. Even with that overhead, you could end up with something that is still many times faster and more energy efficient than a conventional chip, without sacrificing reliability.

  80. Re:Selective Accuracy! by TaoPhoenix · · Score: 1

    I see this like a sudo type thing. Default to classical behavior, and on demand you can engage "boost mode". Thing is, it should be Per Task and then you can expect people to get lazy and boost things that shouldn't, like the finance calcs. But if that can all be worked out, it's interesting.

    --
    My first Journal Entry ever, in 8 years! http://slashdot.org/journal/365947/aphelion-scifi-fantasy-horror-poetry-webzine
  81. Voting machines by Timosch · · Score: 1

    Isn't that what Diebold has been doing for years?
    No, just kidding...

  82. World by Anonymous Coward · · Score: 0

    This is _so_ good news for artificial intelligence and robotics folks. So I totally disagree on that sentence about mars rovers..

    World is not an accurate place, so slight drop in computational accuracy does not matter when speaking about adaptive systems.

  83. Sooo... by thetzar · · Score: 2, Insightful

    He's invented analog?

  84. Fudgy-Dah! by WebManWalking · · Score: 2, Interesting

    Nihon-go de amari yokunai hanashimasu. However, I believe that the Japanese expression was pronounced closer to "Fudgy-dah!" in ads.

    I live in the Washington, DC, area. One of the big perks of living here is the Library of Congress. You have to undergo a security clearance to get permission to be there, but once you get that photo id, hoo boy, there sure is a lot of information there.

    I'm a computer programmer (currently working in Web development, as my handle here suggests). Long, long ago, I researched fuzzy logic at the Library of Congress from the original studies that proposed it. (I think that the original papers were from an Air Force study.) It did NOT revolve around lookup tables. It was more fundamental than that.

    Fuzzy logic assigns a floating point number to data that represents how confident you are that it's true. In the early days, the number varied between 1.0 (absolute certainty) to 0.0 (not a clue, wild guess), or even -1.0 (absolutely sure that it's not true). The exact range used is unimportant except that it's well-known. Of course, almost all of these numbers are between whatever limiting numbers you set, representing shades of gray. That's where the term fuzzy came from.

    We like to believe that knowledge is a deterministic process, but to believe that, we have to ignore our fundamental assumptions, which force us to admit that we don't really know for sure. Fuzzy logic seeks to improve decision-making by acknowledging that fuzziness and quantifying it.

    We all know that we have to multiply percentages to derive percentages based on multiple criteria. If roughly 1 in 2 people are male and exactly 1 in 2 have characteristics above the median, we derive that roughly 1 in 4 of all people are males with intelligence above the median for males. But how confident are we in knowing that?

    Say, for a given population, the 1-in-2 statistic for males is about 97% likely to be true. The 1-in-2 statistic for being above the median is 100% likely to be true, because that's the definition of median. So when you combine the 2 criteria, the 1-in-4 statistic still has a 97% likelihood of being true. In other words, fuzzy logic is a completely independent, parallel computation based on the confidence factors that travel with the data.

    The fact that confidence factors travel with the data is an important part of fuzzy logic. You never throw the confidence factors away and say "That's it. We got the inference we wanted. It's over 95%. That's close enough, so we're going to treat it as true." If you do that, you've gained no wisdom whatsoever from tracking confidence factors. You have to remember that there's still a 5% chance that you're wrong. So all inferences also have their own confidence factors, which are also not thrown away.

    To take an Air Force example, in deference to my vague recollection that they sponsored the original study, satellite surveillance reveals that a bunch of bombers are heading north in Russia. Is it just an exercise, or first evidence of an attack? You have to factor in a lot of unknowns. What's their air speed? How likely are they to be carrying a payload at that speed? Even if they appear to be carrying a payload, how likely is it to be a full dress rehearsal, with ballast for realistic plane handling? The list goes on and on. As part of standard readiness, the confidence factors of these questions have been calculated and recalculated on an ongoing basis. NORAD sees the scenario and looks it up in a scenarios book. As a result, they decide not to change the DEFCON, but they read ahead to see what to do if the bombers leave Russian air space. Crossing the border has a different confidence factor that goes into the overall calculations of whether or not it's likely to be just an exercise.

    So no, fuzzy logic is not simply using lookup tables. Lookup tables are just a convenient way to organize inferences based on changing conditions in reality.

    Returning to Washington, DC, area fo

    1. Re:Fudgy-Dah! by Jay+L · · Score: 1

      The fact that confidence factors travel with the data is an important part of fuzzy logic.

      Fascinating... thanks for the background. I guess the popular-science books focused more on the end result than the process - which itself ignores fuzzy logic :)

      This sounds a lot like Flying Logic, my new favorite mind-mapping tool. It lets you draw a directed graph of your argument/evidence/etc, with confidence factors, edge weights, and operators. Then you can play with the confidence spinners and see how the (likely) outcome changes.

    2. Re:Fudgy-Dah! by WebManWalking · · Score: 1

      Thanks. Computer science majors take heed, fascinating topic indeed.

      I wish I had done the topic more justice and written this on its own, not as a reply, with a non-Japanese first line. As it is, with its cryptic title and intro, it will forever be buried 2 levels down with a score of 2, and no one but you and I will have ever read it.

      Oh well. I'm glad someone benefited from my research besides me.

  85. Microsoft beat them to it. by dkarma · · Score: 1

    That's how we got the BSOD. :P

  86. Finally a use for fuzzy logic? by Anonymous Coward · · Score: 1, Interesting

    Hmm, I wonder. Most sloshdatters may never have heard of fuzzy logic. It was a fad for bad boolean algebra that went nowhere over many years.

  87. Addressing...oOPS! by dkarma · · Score: 1

    Because little errors in hex calculations are ok 0x000FA1 is the same as 0x000FAB RIGHT?!?!

  88. Cheksums anybody? by Anonymous Coward · · Score: 0

    And how would it compute checksums? Just about everything uses checksums to work correctly now.

  89. Analog? by w0mprat · · Score: 2, Insightful

    Transistors are naively analog. It's ironic that we use them for digital logic locked to a frequency cycle.

    --
    After logging in slashdot still does not take you back to the page you were on. It's been that way for 20 years.
    1. Re:Analog? by Joe+Snipe · · Score: 2, Funny

      Transistors are naively analog

      Oh those simple-minded transistors. When will they learn?

      --
      Sometimes, life itself is sarcasm...
    2. Re:Analog? by Anonymous Coward · · Score: 0

      Thanks for a surprisingly revealing comment. :)

    3. Re:Analog? by Anonymous Coward · · Score: 0

      you mean "natively analog" ?

    4. Re:Analog? by Anonymous Coward · · Score: 0

      Your assumption that he means either/or the one thing or the other strikes me as naively digital.

  90. Exactly by Anonymous Coward · · Score: 0

    The problem is we would need an architecture that distinguishes data operations which can be probabilistic from control operations which must be exact because they do things like calculate offsets into data structures or jump targets.

    This would probably only work if you could reliably set up a dataflow architecture and flow fuzzy data through it. Our contemporary CPU and software methods perform huge numbers of exact integer operations which link together into flow-control effects to address instructions and non-contiguous data. Jumping to roughly the correct instruction or accessing roughly the right memory location in the heap is not going to give you roughly the right program behavior.

  91. Early Pentium 60 fiasco by Darkk · · Score: 2, Interesting

    You probably remember when some scientists noticed it was generating some math error in their applications so they contacted Intel about it.

    Intel's response was, "Well, these are early processors in design and shouldn't affect 99% of the population". Of course the scientists created an awareness of this issue and public generated a stink about it even though 99% of them may never run into the bug that affects their applications.

    So now 15+ years later this pops up saying it is OK to have these errors in non-critical applications for sake of speed. People are going to wonder about these chips in their products when something isn't working right and may cry afoul.

    1. Re:Early Pentium 60 fiasco by complete+loony · · Score: 1

      I don't have a problem with this kind of FPU chip provided the *programmer* has full control over the minimum accuracy of the numbers being calculated. I could see this working for example if a new type of floating point was added to the programming language / compiler that specified a minimum level of accuracy so the assembler can choose which FPU should process the calculation.

      --
      09F91102 no, 455FE104 nope, F190A1E8 uh-uh, 7A5F8A09 that's not it, C87294CE no. Ah! 452F6E403CDF10714E41DFAA257D313F.
  92. Probabilistic Computing by hdon · · Score: 1

    You already use this technology. In fact I remember encountering this for the first time when writing an AppleScript program in sixth grade to help a room full of students add up Giant Eagle receipts. I was very embarrassed to have no explanation for someone suddenly getting $54.2300000001 on the screen (looking back, our computer teacher probably should have been able to offer us an explanation.)

    If you are listening to music on a portable media device, it's safe to say that you aren't going to be able to hear the difference between the lossy format and the lossless format.

    It's like drinking from a well. Connoisseurs may claim to be able to taste the difference between it and tap water, but that's just the extra tang from all the bull shit.

    If you float in the well, does that make you a witch?

    Please don't confuse "lossy" media compression with whatever Krishna Palem's technology is going to do. First of all, you can definitely hear the differences if you own a nice pair of cans and a pocket-sized amplifier.

    If the technology gets off the ground, expect to see encoders (or even entirely new codec formats) designed to take into account the nuances of specific probablistic computing machines. Personally I will be a little shocked if the notion that a probablistic general-purpose computational device can outperform any hardware specifically designed for decoding multimedia. So that's where you'll probably see the technology going: hardware media decoders (and maybe encoders, too, for real time applications like portable gaming.) Some computational scientific research takes advantage of probablistic analyses, too, so maybe we'll see a niche for these machines in the supercomputer market. Perhaps there is even a home for this technology in Hollywood CGI (raytracing is expensive, and there are already people using probabilistic algorithms to do it faster.)

    But honestly, can anyone think of a potential application for the average PC of this technology that isn't media codecs? No, because there isn't one. When is the last time a new computer even batted an eyelash at the CPU power it takes to decode audio and/or video? I've been rolling with a 1GHz processor for years and I still can't make out the bumps in my CPU usage meter caused by my media player. If you can: you're using the wrong codec / decoder / media-player.

    With regards to music, they're not talking about skips and pops, they're talking about extremely slight modulations in pitch or, in the case of video, a very slight difference in color.

    With respect, you have no idea what they're talking about. I can promise you that if I ran an MP3 decoder on a PC emulator that introduced noise into the lower bits of every computation, before it horribly crashed the noise it put out could not be uniformly characterized by any "slight modulation" or "slight difference." You're probably asking yourself why this matters because surely that is not how anyone proposes to use this technology. Hopefully you're now realizing what this implies: if you'd want to take advantage of this technology, you would have to write your code to specifically tell the processor which operations and registers can deal with a little bit of garbage. Great. I can't wait to code for that.</sarcasm>

    If I could get 30x the battery life out of my laptop by accepting imperfections in the video it displays and in the audio it plays (and I know it wouldn't, but this is a hypothetical), then I'd gladly go for it.

    You can't. Sorry.

    1. Re:Probabilistic Computing by Firethorn · · Score: 1

      Please don't confuse "lossy" media compression with whatever Krishna Palem's technology is going to do. First of all, you can definitely hear the differences if you own a nice pair of cans and a pocket-sized amplifier.

      And what percent of people running around with MP3 devices HAVE a 'nice pair of cans' instead of cheap earbuds, and I have to say that I've NEVER seen a 'pocket sized amp'. If you do this, you're going to have to face it: You're an audiophile and relatively out of mainstream. You know, the people happy with the earbuds that came with their iPod and 64k MP3 streams?

      In either case we're taking advantage of the notion that NOT ALL of the data is important; indeed much of it is relatively irrelevant to our perception.

      So that's where you'll probably see the technology going: hardware media decoders

      Exactly. This wouldn't be some wierd add-on card or even in your CPU; at least not until long after it's a standard part of Nvidia and ATI's lineup.

      --
      I don't read AC A human right
    2. Re:Probabilistic Computing by hdon · · Score: 1

      And what percent of people running around with MP3 devices HAVE a 'nice pair of cans' instead of cheap earbuds, and I have to say that I've NEVER seen a 'pocket sized amp'. If you do this, you're going to have to face it: You're an audiophile and relatively out of mainstream. You know, the people happy with the earbuds that came with their iPod and 64k MP3 streams?

      In either case we're taking advantage of the notion that NOT ALL of the data is important; indeed much of it is relatively irrelevant to our perception.

      No, not irrelevant. Remember that thing about patting your head and rubbing your tummy? That used to be a relevant example of a practical neurological limitation of the motor cortex (IIRC.) Pianists used to be one of the only groups of people who could do this easily. Today everybody types and uses a mouse and/or plays video games, and that's not challenging to anybody anymore.

      Conversely there have now been studies (which I have been unable to find via Google for some time and I've been severely regretting lately) that show a waning capability of people to tell when and how an image has been stretched. This is due to the prolific presence of widescreen video displays that stretch pictures inappropriately and are robbing people en masse of that particular neurological faculty.

      I do not want to see something similar happen to our musical perception.

    3. Re:Probabilistic Computing by mollymoo · · Score: 1

      You already use this technology. In fact I remember encountering this for the first time when writing an AppleScript program in sixth grade to help a room full of students add up Giant Eagle receipts. I was very embarrassed to have no explanation for someone suddenly getting $54.2300000001 on the screen (looking back, our computer teacher probably should have been able to offer us an explanation.)

      That's not probabilistic computing, that's an artifact of computing in base-2 with limited precision and displaying the output in decimal. It's entirely deterministic and reproducible.

      For working with money use integer cents/pence/whatever and have rules for who gets the remainder. If you do use floating point binary representations, at least round the output for display.

      --
      Chernobyl 'not a wildlife haven' - BBC News
    4. Re:Probabilistic Computing by hdon · · Score: 1

      You already use this technology. In fact I remember encountering this for the first time when writing an AppleScript program in sixth grade to help a room full of students add up Giant Eagle receipts. I was very embarrassed to have no explanation for someone suddenly getting $54.2300000001 on the screen (looking back, our computer teacher probably should have been able to offer us an explanation.)

      That's not probabilistic computing, that's an artifact of computing in base-2 with limited precision and displaying the output in decimal. It's entirely deterministic and reproducible.

      You're right. I didn't mean it literally. I was responding to someone else who was talking about lossy CPU operations.

      For working with money use integer cents/pence/whatever and have rules for who gets the remainder. If you do use floating point binary representations, at least round the output for display.

      I think a better idea is to use a math primitives that support efficient arbitrary precision. Although your way is certainly the norm, but as others have pointed out, the fact that "cents" are the lowest divisible unit of money in meatspace need not hold over in the digital world if you don't want it to.

  93. sure why not by Anonymous Coward · · Score: 0

    In the "new economy" what's the point of accuracy anyway. Spread the wealth! LOL

  94. Article badly misrepresents the idea by Jimmy_B · · Score: 5, Informative

    The author of the linked article has completely misunderstood what this research is about. It is NOT about tolerating errors in the output of computations; that would be completely infeasible. It's about tolerating errors in intermediate values, by using redundancy. For example, three adders made out of unreliable transistors plus a control unit to have them vote, may be smaller and use less power than one adder made out of reliable transistors. However, you can't make everything out of unreliable transistors. In particular, the control unit, and the parts that compare results to each other, have to work reliably and can't be duplicated. That is what is meant by "some information was more valuable than other information", not the low-order bits of a numeric computation.

    1. Re:Article badly misrepresents the idea by sketerpot · · Score: 1

      Are you sure? I found this paper about doing a fast Fourier transform with probabilistic CMOS hardware, with errors making it right through to the output -- but the errors were so small that, for many applications, they are irrelevant. And they were able to get by with 82% less power than a conventional approach with the same precision.

    2. Re:Article badly misrepresents the idea by 1+a+bee · · Score: 1

      Parent must be right.. And I suspect this sort of chip design necessitates the same sort of rethinking about algorithms that near future multi-core processors will demand. There, the emphasis is on parallelization; here, the issue is randomness and probability.

      Probabilistic (or randomized) algorithms have already become mainstream. (I don't know if Knuth has come out with his 4th volume, yet, but I believe he's promised to devote an entire section to the subject there.) The now classic example of a probabilistic algo is the Skip List (1990, Pugh). So it seems natural to extend the domain of "the randomized model of computation" down to the hardware, especially if this randomness comes for free.

      Now, in order to have any faith in a probabilistic algorithm, you need to know something about the probability distribution of the random variables. If I had to guess, an important requirement of this chip design must be that the randomness must not be a function of input (else, that would open an algo to pathological behavior on certain inputs).

    3. Re:Article badly misrepresents the idea by homer_ca · · Score: 1

      You're right about the control unit. A slight loss of accuracy in the ALU is one thing, missing a branch or fetching the wrong memory address is something else entirely.

    4. Re:Article badly misrepresents the idea by Anonymous Coward · · Score: 1, Informative

      The errors are not completely random, so 3 adders combined with voting doesn't help your accuracy. If you are using these kinds of adders you're better off just using one, and accepting the error rate in the results.

  95. Minority Report by FloydTheDroid · · Score: 1

    As we move to more parallel computing something like this might be useful. Kind of like how the Minority Report (book not movie) would throw out results which were out of step with the majority we could have chips with cores running the same code in parallel and then throw out the bad results.

    Of course it wouldn't be right all the time. But don't blame it! You're the one who wanted it 7x faster.

  96. are least significant bits really insignificant? by pikine · · Score: 1

    For example, if I have to reference data structure by pointers, then off by one means I reference the wrong data. If the wrong data is expected to contain a pointer, then it will be totally wrong and I get segmentation fault. If I write a for loop for (i = 0; i lt; n; i++) {...}, and the least significant bit is ignored, then the for loop never makes progress (and never terminates). If i is only successfully incremented 50% of the time, then the for loop runs twice as much as it needs to run. Suppose you are copying files with region indexed by i, you may copy the same region multiple times. How is that faster and more efficient?

    Sacrificing accuracy is so far only applicable for floating point computation, and in many cases this sacrifice has already been made. Some hardware lacks IEEE 754 rounding, and I don't think most people would notice that. Most people just use a double or even long double, which seem to provide satisfactory numeric accuracy for most purposes, and don't bother with error analysis of their code.

    Last point, if you're going to write a banking system, please under no circumstance use floating point to represent balances. Use an arbitrary precision integer library such as GMP, which works similar to representing each number as a string with arbitrary length but is implemented in a more compact binary format.

    --
    I once had a signature.
  97. How about memory? by Guppy · · Score: 1

    I was thinking... what if we applied this to memory instead? Sacrificing reliability for a speed/cost/power? It would be disastrous for executable code of course, but maybe worthwhile for things like music or video. Then again, maybe we're already heading in the general direction, looking at MLC vs. SLC flash memory.

    1. Re:How about memory? by mysterons · · Score: 1

      This has been done already. Look at "Bloom Filters" which you can think of as a randomised way to store information. You might make errors (for example, you think you stored an item when you never did) but the space savings can be vast compared with traditional exact representations. (Probabilistic counting is another randomised algorithm and has been used in cases when you want to count in log-space directly, but at some given error rate).

  98. Oh God, please don't corrupt audio any further... by dontmakemethink · · Score: 1

    It's bad enough that we've effectively lost the top octave (10kHz and up) to widespread lossy compressed audio, the bottom three octaves (160Hz and down) to widespread use of computer speakers and earbuds, now you're going to introduce random noise?! Speaking from a music production perspective it's already got us badly handcuffed, not to mention every idiot with Garageband thinks they don't need to hire a pro to make their platinum album.

    What's really scary is that the auditory capabilities of the entire market can actually degrade from widespread exposure to poor audio, to the point that people literally cannot appreciate good sound. Your ears are not microphones, they are more like keyboards with over 20,000 keys that give the brain information for it to generate the sound you hear. That's right, you are hearing your brain's interpretation of the waves, not the waves themselves.

    As the standard of audio quality degrades, so will the brain's ability to appreciate music. There are important subtle cues that are critical to music sounding lifelike instead of synthesized that are already suffering at the hands of lossy compression, if further artifacts are introduced, engineers will probably have to add a more natural noise to the recordings* to mask the artificial noise.

    Here is a great article that should shed some light on how music affects the brain. In short, music is most effective by creating and then satisfying anticipation. There's no question random artificial noise severely handicaps that process. I gave up my LP's long ago, I don't want those snaps crackles and pops back!

    * We actually already do introduce natural noise to cover artificial noise and have been for decades. It's called bias for analog tape and dithering for digital formats. However, that is a necessary evil for the sake of the recording equipment, and much less significant than the noise random errors would create, even if only to the lower-order data. The noise would have to be constantly as loud as the loudest possible random artifact.

    --

    War as we knew it was obsolete
    Nothing could beat complete denial
    - Emily Haines
  99. Video - another bad example. by Animaether · · Score: 1

    Yes, it's great if it's just a random single element in a random single pixel that fluctuates just slightly. But that's not where any inaccuracy is going to be from such a chip as all -that- stuff comes from the screen drivers which are already blazingly fast. Any gains would have to come from the decoder chip and that's where you're going to run into trouble with bits changing - even LSBs.

    Open a JPG file, change a random bit somewhere, re-display. If you're lucky, you see virtually no change. If you're unlucky, the entire image -after- the point where you changed the bit will have changed colors (subtly or radically), shifted, become a complete mess or - if you're really unlucky - your JPEG decoder will tell you that the resulting output mismatches the spec for the jpeg (e.g. the headers tell the thing it should be an 800x600 image but while decoding the data it concludes the data ends up being 800x608; whoops.)
    ( for the curious - yes, that's how some of the more obscure 'jpeg repair' apps work, finding the likely start of corruption and fiddling with bits until you get an acceptable result that you can then retouch if needed ).

    And that's just JPG. Now try that with any moden -video- codec where encoding isn't just spatially based, but also temporally.

    No, you don't want to have random bits changing in lossy compressed streams. It's a world of hurt.

    1. Re:Video - another bad example. by Firethorn · · Score: 1

      Open a JPG file, change a random bit somewhere, re-display.

      You're not changing just the LSB there, you even have the potential to be changing framing information and such.

      The trick becomes of 'just how more inaccurate is this at calculating LSB? How much faster is it? How much power does it save?'.

      I see this as being used less in video codecs and more for final display or 3d calculations where the image gets refreshed from central(and dependable) sources each frame. Such as for 3D games.

      --
      I don't read AC A human right
  100. And this is a major step forward in the research by 3seas · · Score: 2, Insightful

    .... of artificial intelligence.

  101. Not really intended for a CPU... by Firethorn · · Score: 1

    Nice rant, but I've already mentioned that this sort of thing:

    In all probability this would never make it into usage as a CPU, more likely a dedicated section of silicon performing the function of a GPU/FPU/DSP. Actual control instructions would be high-integrity, just the low significance digits would get the 'cheap but a bit more unreliable' methods."
    Exactly. This wouldn't be some wierd add-on card or even in your CPU; at least not until long after it's a standard part of Nvidia and ATI's lineup.

    There are areas where you need the standard high-reliability silicon, and there are areas where you don't. instruction processes need the good stuff. Though I'll note that even THAT silicon has an error rate; it's just very low, and I imagine much of the extra power is from fail-safes to catch even those.

    --
    I don't read AC A human right
  102. Government by Anonymous Coward · · Score: 0

    You work for the government

  103. yeah.... by Anonymous Coward · · Score: 0

    learn the design of human brain.....
    do u forget things?
    hahahahaha.........how much electricity u need?

  104. Better Brief Summary by enbody · · Score: 1

    Here is a better, brief summary of the work. It shows a standard, deterministic processor with the probabilistic processor as a co-processor.

  105. Real Time Control Systems by archer120x · · Score: 1

    This is great for real time control systems. Your system always has random error anyway, you are continually trying to compensate for this random error, and you are trying to do it really fast.

  106. Sight doesn't necessarily bring enlightenment by Anonymous Coward · · Score: 0

    You obviously missed the whole point.

    Show me another interface that is that fluid and snappy doing those same things.

    Then again, clueless comments are normal here on /. :)

  107. Random Mistakes are... Good? by Anonymous Coward · · Score: 0

    Would make the GUI more lifelike and perty in my opinion by adding random mistakes... like the spots in marble and could be used by programs to generate random events, like faces or the objects in games.

  108. Combine it with multiple slow CPUs by Anonymous Coward · · Score: 0

    Why not have this super-fast inaccurate CPU run at full speed to prepare ahead of time results or branch targets. Those results could be used by some slower but accurate CPUs to perform computations in parallel. and verify the results. If something goes wrong and some of the calculations performed by the fast CPU prove to be wrong, just use the results from the slow CPU and scrap the results that used the false data as input.

    This way the whole system can run in more-or-less the speed of the fast CPU but have accurate results.

    I read a paper on this idea some years ago.

  109. Been there, done that... by lcllam · · Score: 1

    Windows has been thriving on random errors for the better part of 20 years!

  110. Is LSB Error Guarunteed? by BigAssRat · · Score: 1

    Are all errors guaranteed to be in the least significant bit? What happens if it is in the most significant bit? What happens when you are doing AND/OR operations? I don't think any errors on such things would be necessarily good. "Gee, I can never seem to know what whether or not that option will be turned on in the program since the processor has intentional random errors."

    What am I missing here?

  111. Re:Oh God, please don't corrupt audio any further. by Aphoxema · · Score: 2, Insightful

    You say what you say, but for the life of me, I have never felt concerned with the supposed quality of audio. I just can't tell the difference between 128kbps and 256kbps, MP3 from FLAC, 22khz from 44khz.

    I also can not tell the difference between HD and upscaled SD when in motion.

    It just feels so ridiculous, I swear people are only fooling themselves in this high-def nonsense. I can't be sure of that, maybe there really is something I'm missing I'm unaware of.

    --
    "Most people, I think, don't even know what a rootkit is, so why should they care about it?"
  112. Anonymous Coward by Anonymous Coward · · Score: 0

    No. JPEG, MPEG and every other lossy codec sacrifice accuracy for size, not speed. Compressing and decompressing data in that way is slower, not faster.

    1. Re:Anonymous Coward by clone53421 · · Score: 1

      In the era of slow internet, the extra time required to decode a JPEG or MPEG was dwarfed by the time saved by not transmitting the raw, uncompressed data over the phone.

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
  113. Already here by Builder · · Score: 2, Interesting

    We already have accuracy issues with the processors available today. I've worked with quant teams who will insist on only having machines with Intel processors in their compute farm, because they get a different result from the same code running on AMD machines. As the business has signed off the Intel numbers, Intel it is.

    1. Re:Already here by locster · · Score: 1

      How ironic then that while these quants were specifying the need for high accuracy calculations, that the maths turned out to be fundametally wrong in a spectacular fashion. They would have done far better if they'd simply spent an evening or two reading Mandelbrot or Taleb. Ho hum.

  114. And nonsensical applications again.... by gweihir · · Score: 2, Interesting

    In order to stream auto or videao meaningfully, you need to play/display the contents. This has energy consumption high enough that energy savings in the computations will not matter at all before long. In addition, such a chip will allways be very special purpose and most IT experts will not be able to programm in. I call this a dead end.

    --
    Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
  115. Seperate between precision or fuzzy math. by Calyth · · Score: 1

    Maybe having the ballpark at $13k is good enough. Maybe having the Red in a pixel at 240 is good enough compared to 255. But how is the chip going to tell that making a jump to 0x389519B0 - some offset requires full precision, compared to, I dunno subtracting this number because someone punched it into the calculator program.

    And at the end, CPUs calculate a lot of these integers for indexed jumps, and branches very frequently. How's the hardware going to be able to tell when it can skimp and when it cannot?

    When it can't, it would be trying to run linux on known bad ram. Things will crash, and people won't be happy. If you need software to hint, then you might be able to code a compiler to do it for you, but even then, the people who knows which addition need full precision and which one doesn't is the application designer. The compiler won't read your minds.

    If they say, they'd split this into 2 sets of arithmetic instruction, then they're not going to get the power efficiency they were looking for anyways.

    1. Re:Seperate between precision or fuzzy math. by Anonymous Coward · · Score: 0

      Were people this retarded when GPUs first came out?
      "Well SURE you can do all those calculations faster on that chip, but what about all the CPU-specific functions? HOW WILL WE KNOW WHICH CHIP TO USE?!"
      And how would splitting it sacrifice power efficiency? Just how much power does it take to say "Hey, these next 10,000 instructions decode a JPEG, send them to the RPU"?

  116. Fast Sloppy GPU, Accurate CPU? by billstewart · · Score: 1

    If you really don't need more than 3 significant digits, slide rules use surprisingly low power :-)

    Most computers these days have separate processors for graphics and a main CPU, and fairly often the GPU is a lot more powerful than the CPU. Perhaps the place to use the fast low-power less-accurate chip is in the graphics (at least in all the shaders and pixel-bashers, though not necessarily in the geometry calculations)?

    --

    Bill Stewart
    New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
  117. Intel should sue them! by topologicalanomaly47 · · Score: 1

    They have invented this technology long before, end even implemented it in some Intel Pentium processors :)

    God forbid the day when my computer decides how accurate my calculations need to be !

    http://en.wikipedia.org/wiki/Pentium_FDIV_bug

  118. Music DSPs needs to be exact! by Terje+Mathisen · · Score: 1

    The original article is basically describing analog computing, where the most significant bits/digits are always correct, but the noise floor can/will eat the least significant parts, right?

    I optimized the world's fastest Ogg Vorbis decoder back in 2007, and verified the results of my SIMD code by comparing the 32-bit floating point value of each resulting sample with that from the reference decoder:

    Even though many parts of this process works very well with just 16-20 bits, and on something like a GameBoy 12-bit is perfectly fine, there are some very crucial steps in the algorithm that needs to be bit perfect:

    The most important one is where the frequency envelope is approximated by a set of Bresenham-style line segments, and every single bit in those calculations _must_ be identical to the reference bits, otherwise the final audio will diverge rapidly.

    What I'm trying to say is that probabilistic computing only works for some specific algorithms, and that it can be very hard to determine which is which up front.

    Terje

    --
    "almost all programming can be viewed as an exercise in caching"
  119. The Dark Side of The Force do I sense by Anonymous Coward · · Score: 0

    Feel right it does not.
    Born is Darth Vader!

  120. Future by Kim0 · · Score: 1

    By doing noisy calculations twice, or more, or slower, the errors can be decreased a lot.

    This is the same effect as in reading of DNA, where it is read several times to remove errors.

    I guess that for low power processors of the future, there must be methods to adjust these trade offs between accuracy, speed, and energy use.

    I can think of several ways of doing this by traditional programming.

    Kim0

  121. I don't think anyone has mentioned VSTs by Cowboy+Deejay · · Score: 1

    ...virtual analog synthesis. A soft-synth designed around one of these cpus would probably sound more like a real Moog, Prophet V, etc. than any VST currently available. Virutal analogue filters and effects would also benefit.

  122. Ghost into the machine by TheDarkMaster · · Score: 1

    The "noise" on transistors is the ghost into the machine. And someday they will wake up

    --
    Religion: The greatest weapon of mass destruction of all time
  123. I remember reading about this last year by zombie_monkey · · Score: 1
  124. Gaming by Anonymous Coward · · Score: 0

    I also thought about "gaming" as the best example for "speed over precision". But, if I think about it, I want precision in games as well.

    If I rund a modern game @1680*1050 in 32 bit colours, each texture of any surface consists of several other maps over each other, as the texture, then light-textures, shadows, normal- or bump-map, put all sorts of shader-effects on top of that and maybe some ability to watch at things that are far away... or very emotional closeups of faces (modern games have very detailed faces)... if put all that together, I think I want those calculations to be precise.

    Let's assume a chain of calculations and there's a 1% variance each step of the calculation... put three, four calculations for the "correct" colour-value of a pixel and I might end up with green instead of blue.

    No clue if my thoughts are correct but I'd say "games" do not really belong to the type of application where I would want "speed over everything".

    Just imagine you are sent out on the first quest to kill rats in the cellar and suddenly you face the dragons because the computer... err... ;)

  125. Re:What good is a processor that can not be verifi by mysterons · · Score: 1

    Verification in this case means probabilistically proving that the processor will make a certain number of errors, given certain conditions. Since you can make the error rate as low as you want (it could be lower than actual quantum events, for example) this isn't as bad as you might think. Randomised approaches can make proofs simpler than deterministic versioins.

  126. Probable future? by Loki_666 · · Score: 1

    Hi! I am fr*m the futurE and i ha3e one of these probabilistic comp--uters, and i must say they are great, murble murble murble. Low power but fast ÐÐÐÐ and we now use them almost everyw]here.

    Of course Excel had to g0, but since then businessmen have been maki\g decisions based on knowledge and understanding rather than nu>mbers so the whole world() economy has picked up.

    The only downside wa"s last years election where a dog was made president due a far out probability calculation:. Still, this means our current president is not only more l1ked than any previous pr+++esident he also is better looking, and so far has started no wars!!! His last resolution 'Woof' went ^down very well in both the upper and lower hou#se.

    PS: Sorry for the text errors... these things happen, but you get used to &$it.

    PPS: Heart of Gold drive currently under development!

  127. Re:What good is a processor that can not be verifi by mlwmohawk · · Score: 1

    Verification in this case means probabilistically proving that the processor will make a certain number of errors, given certain conditions. Since you can make the error rate as low as you want (it could be lower than actual quantum events, for example) this isn't as bad as you might think.

    Randomised approaches can make proofs simpler than deterministic versioins.

    That sounds like typical "fuzzy" drivel. You can't establish any probabilistic base line for errors without an accurate proof.

    This is sort of the difference between quantum physics and old-school physics for which Einstein's famous quote "God does not roll dice" originates.

    I would argue that quantum physics as we currently know it will become more accurate as we continue to understand the realm which we have discovered. It is so different that our ape brain is a bit at a loss for a conceptual backdrop.

    Similarly, abandoning "accuracy" in computing is a bad idea. A "good" engineer or scientist can estimate a number of things easily to lightly test viability of an idea, but must eventually prove the concept.

    A computer and/or system that does not accurately process information and can, in fact, return non-identical answers for identical problems can not be trusted. Most computing involves many calculations, be it animation, banking, science, or what ever. Introducing little inaccuracies at each stage will multiply into larger inaccuracies.

  128. Majority Voting by Anonymous Coward · · Score: 0

    Why not use a majority voting system with such a processor?

    If this processor goes 7 times faster than a regular one, and you perform every computation 3 times and take the most common result, you now have a processor twice as fast, and just as accurate, as current ones.

  129. little-endian by DavoMan · · Score: 1

    I think this is why 'amiga' was one of the keywords. It reminds me of little-endianness. The amiga did stuff with little-endian I think.
    Little-endian means that when number represented in binary, little endian means the left-most bits represent the big numbers, and the rightmost bit means '1' in decimal.

    The computer reads memory from right to left, so when you run little endian, the computer only needs to read in the data it needs..continually reading in data to get more precision.

    I think this concept is well-established in software but this is the first Ive heard of precision being used in hardware.

    --
    Whats the harm in yelling 'Computer, end program!'? You could be living in Star Trek! Go on.. give it a try.
  130. Not even wrong. by argent · · Score: 1

    Your comment doesn't even make enough sense to be wrong.

    The Amiga used the 68000 processor, which was big-endian, as were almost all processor designs, ever. Most computers today are little-endian, because that's what Intel (following DEC's lead) standardized on.

    Computers don't read memory "left to right" or "right to left". They operate in parallel.

  131. Speed not always good by Kazymyr · · Score: 1

    I don't think anyone would want a chip that can calculate extremely fast that a nuclear reactor has a probability of failing in the next year between 50 and 99%.

    --
    I hadn't known there were so many idiots in the world until I started using the Internet -Stanislaw Lem
  132. Re:What good is a processor that can not be verifi by mysterons · · Score: 1

    There is nothing "fuzzy" about this line of reasoning at all. Take a look at the book by Motowani and Raghavan ("Randomized Algorithms"). There you will see various kinds of randomisation: for example, you can have a randomised approach which is always deterministic in the answer, but may take a variable amount of time. (Randomised versions of Quicksort do this). Or, you can have another type which may make incorrect answers, at a given error rate. Probabilistic counting is of this form.

    Now, you can turn a program which makes errors into one which does not make errors by repeatedly running it. In the case of probabilistic counting, you might do the whole thing many times and report the average. So, you can trust it: you just need to know what the probability of error is.

  133. Re:It seems like when you need a precise calculati by ucblockhead · · Score: 1

    There is no room for any error at all in a financial transaction. Financial calculations must always be exactly precise. You can't just reduce the error unless you are reducing it all the way to zero. And not a statistical zero, but an exact "NO ERROR" precision.

    --
    The cake is a pie
  134. Re:It seems like when you need a precise calculati by j-beda · · Score: 1
    "Wouldn't it need to be 2 others as in 'minority report'?"

    I have heard that for a ship's chronometer the recommendation is to carry either one or three.

    With one clock, you just use the time it displays and hope it is accurate. With two clocks, if they disagree the only thing you know is that you don't know what time it is and you don't even have a chance of knowing the correct time. With three clocks you can be fairly confident that only one at a time will be off.

  135. Wow - BAD Example by sjbe · · Score: 1

    Using bank balances as an example of where accuracy isn't required? Seriously? I want whatever drugs the person who wrote that article summary is taking because it must be really good stuff. I'm a certified accountant and believe me there would be hell to pay for even a one penny error in financial calculations. I can't think of a worse example to illustrate inaccuracy being "helpful".

    BTW Financial calculations are almost never done using floating point. They use integers on both sides of the decimal point to whatever precision needed precisely because using floating point will inevitably result in an error. It's a pain but it's absolutely necessary because you don't dare have an error of even $0.00001 cents.

  136. Graphx by Anonymous Coward · · Score: 0

    Would be cool for graphics.
    For say, netbooks with a lossy GPU - consume less power, I could imagine some floating point mis-calcs will lead to some texture banding, some shifts in polys but well worth it to render a huge scene and have some ignorable artifacts.
    Imagine an Iphone rendering quake 4, could be cool.

  137. Re:What good is a processor that can not be verifi by Anonymous Coward · · Score: 0

    I'm sorry you have such standards, as not even Real Life (TM) can live up to them.
    I suppose you never go to a live performance of any kind, as those newfangled HPUs (Human Processing Units) have a margin of error much higher than 1%. I'd guess also that you never listen to music through the horribly inaccurate medium of air, and rather have it plugged directly into your head. Further, I can only assume that you are a robot, as you would never let such a non-determinate thing as a brain process your input.
    You want to know what good these processors will be? Say I'm making a game, and I want a certain type of grenade to produce a visual effect that involves hundreds of thousands of sparks flying through the air. For each spark I'll need to calculate a trajectory and pass that along the pipeline to the graphics card, which will fill in the pretty details.
    Let's say on a normal processor we calculate these trajectories in three seconds, and they're all PRISTINE. Now say we send those instructions to this new processor, taking only one second, BUT we now have about a hundred sparks one millimeter from where they should be.
    Maybe at this point you will pause the game, eye the grenade discerningly, and ask me about the rogue sparks, but those of us without robot brains will fail to notice.
    So, yes, you do need to be able to repeat SOME calculations, but there's a lot of crap in this world that while it doesn't 'matter' it needs to be calculated.

  138. Bistromathics by Anonymous Coward · · Score: 0

    It has begun:

    "Bistromathics itself is simply a revolutinary new way of understanding the behavior of numbers. Just as Einstein observed that space was not an absolute, but depended on the observer's movement in time, so it is now realized that numbers are not absolute, but depend on the observer's movement in restaurants."

    http://www.angelfire.com/nj2/once/math.html

  139. Proof at last... by Roadkills-R-Us · · Score: 2, Funny

    ... that the economy is now based on Monopoly money.

    Now when you log on to your online banking account, you'll get a Chance card:

    Bank errors are in your favor... at the moment.

  140. Can't wait for... by TemporalBeing · · Score: 1

    ...the Improbability drive to come out. Or better yet, the Restaurant Probably drive (did Adams give it a name?)...

    --
    Truth is like the sun. You can shut it out for a time, but it ain't goin' away. - Elvis Presley (source: imdb.com)
  141. Re:What good is a processor that can not be verifi by clone53421 · · Score: 1

    So, of what use is a processor for home or office that does not compute accurately. Music should sound the same each time you play the same "image.". Graphic images should look the same every time you view them. Checkbooks should balance, and don't use this device on turbo tax.

    The ear and eye are notoriously easy to fool (MP3s? JPEGs?). And no, you obviously wouldn't want to use "fuzzy" logic to calculate your TurboTax filing.

    --
    Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
  142. Re:Oh God, please don't corrupt audio any further. by dontmakemethink · · Score: 1

    I just can't tell the difference between 128kbps and 256kbps, MP3 from FLAC, 22khz from 44khz.

    That's because your ears (meaning the parts of the brain that interpret sound) have not been trained to tell the difference. If you spent a few hours listening to your favorite music at my audio workstation, you would then be able to distinguish between those formats and appreciate the superior ones moreso.

    I know that sounds snotty, but is Slashdot really the forum for an "ignorance is bliss" argument?

    --

    War as we knew it was obsolete
    Nothing could beat complete denial
    - Emily Haines
  143. Car analogy? by Bruiser80 · · Score: 1

    So would the car analogy be where the motor can run at a higher RPM on less gas, but the car sputters from time to time, with the possibility of the motor locking up?

    Or would it mean more like, a car that goes faster, has better fuel efficiency, but your inputs (gas, brake, steering), doesn't necessarily match the outputs (accel, decel, direction change).


    Going back to a PC running with a processor like this, how does an OS run if a processor doesn't repeatably come to the same answer?

    --
    Arguing with an engineer is like wrestling a pig in the mud. After a while, you realize the engineer enjoys it.
  144. Re:Oh God, please don't corrupt audio any further. by Aphoxema · · Score: 1

    My 'audiophile' friend really did try to change my mind on the difference, and I really did give it a genuine chance. I sat, listened for a while to the different things he played for me. He swore they were different bitrates, frequencies, that there was a clear difference, but I just could not perceive it.

    However, I have had my hearing checked. I can hear a full range of sound, a little better than most my age (3 years ago). I'm fully aware of every little sound that happens around me, I depend on my hearing far more than my sight when walking or riding a bike.

    I'm like a damned radar, I keep my eyes closed when I'm swimming underwater and never run into anything or anyone. I'm fine in pitch black. I can even hear people talk across noisy rooms with high ceilings.

    A lot of noise does frustrate me, like people talking and stuff or cars or sirens. I really do hear everything just fine, it gets really distracting.

    As sure as I am that my hearing is just fine, even better than fine, I swear whatever deity you might care to imagine: I do not hear the difference between these supposed audio qualities.

    --
    "Most people, I think, don't even know what a rootkit is, so why should they care about it?"
  145. Re:Oh God, please don't corrupt audio any further. by Firethorn · · Score: 1

    Even if you could, would you really want to? Would you want to make it so that in order to appreciate music you need a $10k sound system, or constantly visit live performances of classical music to appreciate your range?

    Personally, I can tell the difference between earbuds/computer speakers/surround sound system with proper wattage capacity and amp, but I haven't bothered to set the sound system back up for a while. Heck, I'm at the point I'd probably be better off buying a new one with HDMI inputs for my new TV. A TV that I can't really tell the difference between 1080p and 720p. I know it's better than analog, that blueray has a better picture than good old DVD(and I remember when THAT was new and crushing it's rival Divx).

    How much better of a picture? 100% better? Not hardly - I'd say 10%. For 4X the pixels, I give it 10% in perception. Sad, huh?

    --
    I don't read AC A human right
  146. for a PC, maybe not. for a brain, PERFECT by Anonymous Coward · · Score: 0

    http://www.eweek.com/c/a/IT-Infrastructure/IBM-Researchers-Looks-to-Bring-Brain-Power-to-Computers/

    research into simulating and emulating brains would thrive near-precise computing.

    or cat brain: http://blog.wired.com/defense/2008/12/fruit-fly-guy-j.html

  147. don't offer the choice of accuracy or not by Edgester · · Score: 1

    Oh god, please don't offer vendors and programmers the choice of accuracy over speed. It's one more variable to screw up, and I can just hear the screams from users who don't understand the trade-offs. Vendor: "hey, we can get a 10x speed boost over our competitor by using the less accurate processor. We'll just put the accuracy caveat in the fine print."

  148. Amiga tag? by bjb · · Score: 1

    Now WHY did this get a tag of Amiga? Must be the like a flash mob .. err.. flash taggers or something.

    --
    Never hit your grandmother with a shovel, for it leaves a bad impression on her mind...