Unpredictability in Future Microprocessors

prostoalex writes "A Business Week article says increase in chip speeds and number of transistors on a single microprocessor leads to varying degrees of unpredictability, which used to be a no-no word in the microprocessor world. However, according to scientists from Georgia Tech's Center for Research in Embedded Systems & Technology, unpredictability becomes a great asset leading to energy conservation and increased computation speeds."

Comments

Another use

[physicsphairy]

unpredictability becomes a great asset leading to energy conservation and increased computation speeds

Probably and even bigger boon for encryption and key-generation.

Re:Another use

[thpr]

Probably and even bigger boon for encryption and key-generation.

I vote key-generation and not encryption. Otherwise, how would you decrypt it? (given that the key generation and decryption are non-deterministic with one of these...)

Robots and Unpredictability

[Anonymous Coward]

"unpredictability becomes a great asset leading to energy conservation and increased computation speeds."

When robots have this "unpredictability" tell me not to worry!

The Uncertain Airbag

[rhaikh]

Well, there's a 99.99% chance that airbag shouldn't be deployed right now, I'm just gonna disregard that "1".

We have this now

[drsmack1]

Before I found memtest my computers were VERY unpredicable.

Little problem

[Anonymous Coward]

While certainly many problems can be solved using less than perfect measures, building an entire chip based on this would not work out so well. For example, while a DSP app might deal fine with small variations in results, a device driver or chunk of crypto code is probably not going to be very happy with close-but-not-quite-right results.

Why do I have a feeling these guys have done simulations with single applications, ignoring the surrounding OS environment?

Re:TFA

[krunk4ever]

also, given these are microprocessors, when they have instruction jumps, wouldn't it be a concern if the address they're jumping to is slightly off?

bad story

[msblack]

It's rather a poorly-written article with a lot of 1950's science fiction predictions about the future. The field of fuzzy algorithms has existed for ages. Fuzzy algorithms don't rely on random results. Rather, they use the "p-bits" to perform their calculations. P-bits are not the same as random bits. On the contrary, p-bits are "don't care" or "flexible" values that take into account multiple possibilities at the same time.

Random results are terrible because they are random. The scientific method depends upon experiments that can be repeated by other researchers. You can't base a theory on results that don't correlate with the inputs. You can repeat the experiment to obtain a probablistic model but not certainty.

A computer chip that yields unpredictable results is not going to magically recognize the image of a chair, much less a face because a chip that can't execute a program is more akin to the movie Short Circuit where the appliances go whacky. To me the author confuses the concept of fuzzy algorithms with random trials.

GPU-like rather than FPU-like

[buckhead_buddy]

While FPU calculations still require the precision, reproducability, and speed limitiations currently applied to all CPU chip work, this article seems to be aiming at loosening up the precision of calculations we don't really need right now.

• the initial JPEG lossy compression
  
• the texture mapping of blood splatters in first person shooters
  
• mp3 playback for people who don't care about things like fidelity and consistency
  
• voice compression in internet telephony
  
• barcode analysis when using a symbology developed in the days of 72 dpi printers but where everyone today uses 1200dpi readers and printers.
  
• people deliberately trying to add entropy for security or artistic reasons.

I seriously doubt any accountant, music snob, or cs major would allow the main cpu to become inconsistent, but if Apple or some other trendsetting company offered a new computer with a "Right Brain" chip just for these entropic applications I'd expect it to start a whole new fashion in desktop computers.

Re:Indeterminate Voltage and Bad Fabrication

[zcat_NZ]

"informative" ?!!

Do you have even the faintest idea how logic actually works? Or did I just mis-read what you wrote?

None of the gates have to reliably reproduce that actual voltage (+5, +3.3, +2.8, +/-12v, or whatever) that represents a "1" or "0", they just have to reliable recognise that it's "smallish" (less than halfway, logic 0), or "biggish" (more than halfway, logic 1) and in turn produce a voltage themselves that's reasonably close to whatever represents a "0" or "1". Binary is used for exactly this reason; it's very difficult to propigate an analog voltage through any number of circuits without losing accuracy. Digital circuits don't even try. And as I understand TFA, now they don't even have to get it right all the time either..

Re:TFA

[aprilsound]

There is already a fair amount of computer science research into this. BPP algorithms make use of randomness to deliver a "pretty good," that is, bounded error, polytime answer to problems that would otherwise take NP time.

Error correction

[jmv]

I'm surprised nobody has really mentioned error correction. In the same way that correction codes can work around RAM unreliability, you could have checksums built into each instruction to detect and correct errors. You would basically trade speed for reliability, something that has existed in communications for decades (refering to Shannon's work). I don't see why it wouldn't be the same for CPUs. I also remember clearly Richard Feynman proposing the idea (sorry, don't remember which book), so the idea isn't exactly new.