*Sigh* Why do so many make this assumption, slashdotters should take a few business/industrial engineering courses to understand it's not as easy as just selling another part. Everytime you add a part to your line-up it costs additional money and resources to manage it. Each part may need it's own substrate design, test programs, software support, etc. It also becomes more difficult to manage what you build in terms of inventory and factory loading.
I mostly agree, though I'd note that we're talking about the same chips. There wouldn't be a different substrate design, test program, etc... They're the same chips, just with some non-functional parts disabled.
There will be cases where there is enough difference between parts where it makes sense to create an additional offering (eg disable half for 32-core); but the assumption that a company would segment to each core isn't correct.
I agree, my initial thought for a 64 core die was 4 core increments, with a matching decrease in the reliance on core speed as a metric. 64-60-56, etc...
My rule of thumb is that most people won't notice the difference until the performance is affected by more than 10%. So by that logic, an 8 core difference should be maintained: 64-56-48-40-32. Have two speed levels, that's 10 chips in your lineup. Add in phasing between chipsets, you're up to 20-30, of which 10 or so could be handled with a couple guys in a warehouse for the legacy support customers. Phasing: Cutting Edge-Mainstream-Legacy. People pay through the nose for the fast 64, slightly less for the slow 64, the slow 32 is the 'bargain basement' chip, the fast 32 a slight uprate, etc...
The mainstream ends up buying wherever the bulk of the production is. If 56 cores on average survive, that's where the sweet spot will end up.
Wouldn't it make sense to sell any part that had at least one working core?
On the other hand, if we start seeing more than 8 cores, likely single core processors will pretty much be a thing to the past.
The yield of a 16 core processor with only 1 core functional is likely to be insignificant, to the point that it's not economic to try to sell them.
Let's say that 16 core processor is $320. That's $20 per core, so you'd likely only be able to get around $20 for the chip with one core operational. That's assuming you don't have to underprice them in order to get the economic crowd to not pay the extra $20 to almost double their performance*. Heck, there'd be a reason right there to bin them - They'll move up and buy a higher-profit duo-core instead.
At that point it might be cheaper to bin them, rather than to try to support chips that are less than 10% functional, and therefore likely to be hiding problems.
At $320, there'd still be quite a market for 4-8 core systems, hitting the sub $100 market, and the $150 market quite nicely.
*Don't forget that even for a bargain basement machine, $20 for increased performance wouldn't be much. You still have support components to consider. $400 for a '2 ghz' vs $420 for a '3.8 ghz' would have many bargain shoppers spending the extra $20, only the most penny-wise would buy the cheaper one.
Don't forget that they're usually trying to make chips that operate as fast as they can, they then test the chips to see what they can do and sell them at that rate.
When yields get *too* good, they wouldn't be able to move the number of 'premium' chips they can actually produce at the price point they want to sell them for. Then there's the huge 'economy' save a buck market that they want to sell to.
Solution: disable something, underclock it, sell it for cheap, so you can still get that 10X price for the uncrippled product.
Also bioshock as a game felt unfinished toward the end, the story was interesting for the first part of the game, but by the time you got to Andrew ryan things just seemed to get really weird, and then on your journey to fountain the story loses all cohesiveness really.
How would this distract from it being art, allbeit rushed/unfinished art?
There are plenty of movies that start out good that finish horribly or rushed. Where they butcher the film in the editing room. Some books are like that, where you get the feeling that the auther went 'OMG - I've spent a year on this book' and promptly ties everything up in a two week writing splurge with minimal editing.
Personally, I feel that Bioshock, heck, even the old Space Quest and Hero's Quest type games have more artistic merit to them than some pieces of 'art' like the crucifix in urine*, or the sectioned out cow**. Of course, most of my objection to them is that the government paid for them with tax money. If a private buyer wanted it, great. I just think that if the.gov is buying art, it should stay fairly conservative with it. It's supposed to be a bit stodgy.
*And I don't even consider myself a Christian. **Cool science though. It's just that it should be funded as such, not art.
More efficient is a possability, but I suspect that once you throw in the differential and CV joints you'll lose the weight and cost advantages.
True, but you're not going to loose that much power in a differential, and you might want to have CV joints anyways to keep the weight of the motors as sprung rather than unsprung weight.
A quick search says that a differential will be 94-97% efficient. From looking at different efficiency graphs, such as on this site, you can have percentage differences of greater than 5% between different electric motors, within their optimal power zones.
Personally, it sounds like something for a design team to look at. Don't forget that you'll most likely be looking at hub motors if you're going for direct wheel drive, they're less efficient than a similar power traditional motor with a shaft.
You might be able to figure all this out with a proper design team and simulations, but I wouldn't be surprised at all if they ended up building prototypes to test it out.
The acceleration is could be a big deal. That's based on the flat power curve of an electric motor and it's ability to operate from a standstill. While a gasoline engine is still slipping the clutch (or torque converter) to avoid stalling, the electric is applying 100% torque. The acceleration will probably be a selling feature in the U.S. There's a lot of misperception that electric cars will feel like driving a golf cart.
Agreed. Especially given that electric motors tend to be more efficient the larger they are, under powering the motor doesn't make much sense.
I can well imagine dealers having a demo car with the traction control shut off so they can demonstrate that the car can burn rubber. Because a lot of people don't realise that burning rubber means lost acceleration, there will probably be an aftermarket (legit or gray) for the firmware that lets you do that.
I don't doubt that, though I think that most people willing to change out their car's chips to 'increase performance' will quickly figure out that burning rubber is counterproductive for both fuel economy and acceleration rates. I wouldn't underestimate the knowledge of the average nascar loving hot-rodder. Not that they wouldn't think that spinning tires is cool, but that they'd know that it's not the best way towards acceleration and plan accordingly. Maybe with a switch turning traction control on or off.
On the other hand, go two motors down to the SIEMENS 1LH5118, and you have a 19.7HP continous rated motor that has 90.8 max ft-pounds of torque. Good job finding a site with more detailed specifications on electric motors, most sites only have the continous ratings. I especially like the power curves.
One thing this thread has done is get me to research electric motors a bit more, the number of types they have is staggering. Of course, when you think about it, the average car has at least two electric motors, likely more, and only one IC engine.
Then you figure all the electric tools, compressors, AC/Heating systems, washing machines, computer fans, etc... I wouldn't consider it outragous to find out that there's at least an order of magnitude more electric motors than IC ones. Of course, most of them are very small in comparison to a car engine.
There's dozens of different types, depending on whether it's going to be fed AC or DC, is intended for a constant torque or constant speed despite load, or variable. Whether it's going to be starting/stopping a lot, or hardly ever. Whether it can have a gradual start, or a sprint start.
Looking at the power curves, the electric motor has nearly 100% of it's torque available at a mere 400 rpm, while they don't even list torque for the gasoline engine until 1800 RPM. It ends at 3600 RPM. Meanwhile you find motors rated between 3500 and 10000 RPM. Combined with the low speed torque, an appropriate reduction gear might be able to eliminate the need for shifting. Going by the graphs(150-125), for efficiency sake you'd simply want 25mph correspond to ~2800 rpm. Then 75 mph would be ~8400 RPM, which is within standards. Well, for the MES 200-250, I'd peg 25mph at 2000 rpm, giving 75mph at 6000 rpm. You'd have plenty of overhead still with those motors. Efficiency above 90% for much of it.
obviously gas, makes more torque, electric makes more controllable torque. (for similar HP rating, with correct gear reduction for each)
Show me a reference that says that a gasoline engine of a given HP rating produces greater torque than an electric motor of the same HP rating. Especially across the range that an electric motor is capable of exerting that torque.
Electric motors generally crap all over gasoline engines when it comes to torque, especially at low RPM levels. If it wasn't for how lousy storage methods are for electricity, we'd have been using electric cars for years.
So I can buy that, if their not rated equivalently and you want a single accell (which is likely for a car) And your not so worried about efficiency (run electric out of it's rated torque you lose efficiency big time)
then their is something, you can under rate the electric motor, as long as you rate your supply (battery?) equivalent to the gas motor.
Indeed, we're looking for acceptable acceleration profiles. zero to sixty is one good measurement, but I'd look at 0-35 and 0-75 as well. We're not looking at drag strip performance, we're looking at 'The red light just turned green'.
Now, does it make some sense that an electric motor, capable of producing 3 times it's rated HP for something like two minutes would produce better acceleration curves than a gasoline engine with three times it's HP? At least in the 0-85mph range than street cars operate in?
If your driving habits are worse than average(towing, lots of steep hills), you could go for two to one. If you regularly go 100% throttle using a gasoline engine on hills in your area, you might go one for one, but then there's questions of whether you sized your gasoline engine right.
Batteries are normally rated by total energy storage - their ability to supply power is easily sufficient once you've budgeted enough to get yourself a decent range.
As for efficiency, electric motors have an efficiency curve much like computer power supplies. They're generally very efficient around 100%, less so at 50%, not very efficient at 10%. Efficiency would be indeed be absolutely lousy at 10x the rated power.
Thus why the 'rule of thumb' is limited to 3x - for one thing you can't go 10x for long, seconds at most. It does trade off some efficiency during acceleration for efficiency during cruising. The idea is that the extra 3% efficiency you gain during the 10 minutes cruising at a constant speed is worth the 50% loss of efficiency during 10 of the seconds spend getting to that speed.
With a controller set to 'efficiency', it wouldn't go over the motor's ratings under normal circumstances. Sure, it'll overdrive the motor if you stomp the acceleration pedal from something like 30mph until you hit 75-80 mph, but if you've sized it so that 100% is 'constant 75 mph on level terrain', you'll be just fine.
You achieve similar road driving performance with a electric motor rated with 1/3 the HP of a gasoline engine.
Electric motors are rated under load at maximum sustained power. Gasoline ones are measured unloaded peak power. Thus, a '25 hp' electric motor can operate as a 100hp one for a short period of time. This time is limited by heat generation. A good controller will have a heat probe much like the sensors for CPUs today, and limit power before the heat is enough to cause damage. This can be extended out with active cooling, if necessary. The Tesla electric car motor has a fan, for example.
The vast majority of vehicles don't operate at anything near their peak level except for brief periods of time. For example, I still have ~ two thirds of my throttle to go in my four banger at 75 mph. So at max speed I'm operating at ~33%. Multiply by three, I'd be operating an electric motor ~100%, it's most efficient loading. I wouldn't be able to do 80 mph for long periods, but I'd still be able to pass other traffic.
If I live in hill or hot country, I might want to use a 1/2 figure instead. As is, I've been forced to downshift on some steep hills to maintain speed. In an electric vehicle - as long as the hill's short, I'll be fine. If it's a long climb, I might have to slow down.
One engineering issue with this would be that the 100 hp motor* will tend to be cheaper, lighter, and more efficient than two or four individual motors. Remember, most cars on the road are only two wheel drive. With the slip differential, it's effectively 1 wheel drive(the tire with the worst traction gets the most HP).
So you have to look at the possibility that having a simple drive train can be more efficient than individual wheel drive.
Though given the efficiency scales, a two motor system could theoretically be more efficient at low power by not powering one of the motors. Though I imagine that you could do sort of the same thing with a larger motor by only powering part of it.
*This would produce a very fast accelerating electric vehicle. I've read that an electric motor with 1/3 the HP can give you equivalent performance to a gasoline engine. IE 30 HP electric = 90 HP gasoline.
I'd tend to say that you have more to worry about than electric cars. Most modern cars are far quieter today than they used to be. Engine noice is no longer significant.
An electric car at high speed is still going to emit a fair amount of noise. Modern gasoline and even diesel engines are very quiet even at low speeds.
For the motorcyclist's 'being noisy is safer', well, you still have to worry about deaf people, even half-deaf elderly who are running around in a relativly soundproofed car. With the radio turned up.
Russia will sell just about anything to anyone with enough cash, including blueprints, plans, and technology. China probably isn't that far behind technologically, honestly. Radar and EW systems are certainly the US's strong point, but it would be unwise to assume that technology that's 40+ years old is unattainable by other nations.
For that matter, there's no reason other than distrust to simply buy the satellite data from either Russia or China. I'm sure they spend the effort. After all, they both have active space programs.
Still, a stealth satellite or three could serve the purpose of making them spend the effort. The idea being that putting the stealth satellites up there makes Iran* spend proportionately** more effort tracking and avoiding them.
*Simply picked as an example, North Korea would work as well. **While the satellites would cost more than the tracking, the US has so much greater resources that it'd still be a win for us. A $50k missile is cheaper for us than a $5k truck for most countries, proportionately.
The parent was talking about having the warranty service diagnosing hardware issues do it in a fashion independent upon what the customer has done to his HD.
By booting from your own drive, you eliminate any software issues, and can even have automatic access to any specialized diagnosis tools.
If the issue is suspected to be the HD, you plug it into a dedicated HD tester.
What you're suggesting adds a couple hundred to the cost of the system for little benefit. For the personal user, backing up data(always a good idea), then performing a wipe/reinstall is a good idea - to prevent data theft, if nothing else.
If your choice is a new HD, that's your choice, but new laptop HD's are expensive, especially if they're big.
Please remember my point - At least by a non-first world nation.
The United States counts as a first world nation. Iran might not be able to put forth the effort into tracking all these down.
Remember, it's not just the equipment, it's also the manpower to do the analysis.
You'd need to have radar systems to find the objects, followed up by telescopes to confirm the profile of the detected targets. And if you're going as low as a screwdriver, there's an awful lot of targets.
We have stealth aircraft, designed to be minimally observable to radar.
Couldn't we do the same for satellites?
Sure, planes have the advantage of being able to hide in the clutter, but surely there's enough debris up there now that a satellite with the radar profile of a wrench or bolt might not get noticed.
At least by a non-first world nation. And I'd include China in that list. Sure, they have problems, but they do have the resources to do quite a bit.
Then again, why bother? Said non-first world countries also lack the ability to shoot the satellites down, or even interfere with their operation.
It looks like you're trying to be funny, but car lights would actually be one of the lesser offenders. The big offenders would be street lights, of which there are many where there might be a car per hour. Heck, my little town has at least as many street lights as we do people, and our roads aren't even paved.
Besides that would be exterior offices/stores which never shut their lights off, even when they're closed at night(and keep their lot lit). Yes, I know, safety issue, but a motion sensor with a delay timer would work almost as well, and save large amounts of electricity. What I'm thinking of is a system which is like 'last motion' + 5 minutes.
You also have neon/billboard lighting, but in most areas that ends up being fairly minor compared to the others. Other than places like Los Vegas, of course.
Basically, we need to set up an automated system like the home energy saving - shut off the lights when you aren't in the room.
Besides consistency and learnability, using standard dlls can also reduce bloat - a program that tries to reimplement the wheel will be larger, and likely slower.
For one thing, a proper system dll, such as what's used to create standard windows and buttons should be highly error-checked, and therefore stable, not to mention highly optimized to make it faster.
A good 'lean and mean' program should make use of system dll files whenever it makes sense.
Take Media player classic versus windows media player. Both use external code to play their media. That's just fine.
From what I remember, 7 or 8 wasn't bad, then 9 was horrible, 10 is getting better(at least you can hide most of the crud), I haven't used 11.
The creaters of classic realize something important. People want to watch videos more than they want a fancy 'skin' that just gets in the way of playing videos.
For example, why should I dedicate as many pixels to the border and controls as I am the video? I might want to be doing something else with that screen space. And what's up with the majority of the controls being nonfunctional most of the time? Why do I have to hit ctrl-p to play/pause, instead of the nice big, easy to hit spacebar? Why did they shrink the seek bar, making it less accurate/easy to control, while not using the space gained for anything useful?
I'll frequently play a video in the corner of a screen while reading something else. When I'm doing that, I rarely need more controls than a play/pause button, and selecting the screen and hitting space works for that. The majority of the time, the only control visible with classic is the seek bar. It's a nice thin bar across the bottom that also tells me how far into the video I am, that I can easily adjust if I want to.
And therein is the problem; because making a copy in RAM of a computer program, which is made as a necessary step in the execution of the program, constitutes Fair Dealing or otherwise does not infringe copyright.
Yes, but with enough lawyers and a slightly technophobic judge, you could get the argument of the parent.
Personally, I'd argue that a 'copy' exists in RAM as much as a 'copy' exists on the screen when you play a movie. The data is still stored on the media, whether it be a DVD, tape, or film.
Then there's the issue of the HD. The law actually allows you to make a backup of any software you purchase a license for. The lawyers managed to convince a judge/jury that the 'backup' is the copy installed on the HD, thus the copy in the RAM is an infringement.
Games are actually the most likely to get into trouble for something like this; their usage of 'copy protection' that requires the disc to be in the drive for operation and selective copying of files during installation would mean that you don't have a true backup.
They are using stem cells from placentas and umbilical cords, but at the time of birth they're almost like adult stem cells; they're no longer as plastic as earlier term stem cells.
Then there's the whole 'tarred brush' problem - current administrations don't make a huge differentiation between fetal stem cells and birth stem cells. There are also some ethical problems with using the discarded parts of a baby (cord&placenta) in research when the donor is a minor and unable to give consent. You'd think that the parents could give permission, but there are still issues for the really paranoid people.
One suggested source was fetuses that are generated yet discarded at fertility clinics*, not aborted fetuses/babies. That would result in absolutely 'fresh' cell masses, that by design are never going to be implanted to grow into a baby, that right now end up as medical waste.
*Fertility clinics will generally fertilize a half a dozen eggs or so at a time. They do this to increase the odds of getting a viable embryo. Remember, the whole reason somebody would go for artificial fertilization is because something is messed up so they can't do it the natural way, so the odds are good that any given fertilized egg won't be viable. The process is fairly expensive, yet collecting/fertilizing multiple eggs in a procedure doesn't really cost any more. So they do a number at once, select the most 'viable' embryo, and implant that one (or two).
Not much different than nature, really. The odds are slightly against any given fertilized egg surviving to the one month stage, when women usually start figuring out they're pregnant.
A good point; the ethical dilemmas of embryonic stem cell research has resulted in a comparative lack of funds.
Another argument would be that embryonic stem cell research is 'higher level' research - more theoretical than practical. The lessons learned there could filter down and help adult stem cell research develop practical treatments.
For one thing, without some extensive modification you'll have problems with immune systems rejecting the cells; just like with transplanted organs unless you make it a habit to collect them for all children. That's a rather massive storage project, and what happens if an accident takes out your tube of stem cells.
Better to use adult stem cells - they can be harvested anytime, and we can provide service to people today using them.
Sure, my computer isn't currently ready to run a 50kw radio station broadcast.
However, throw some software on it and it can, as long as you don't expect it to be doing the modulations itself(IE output the sound to a board to be transcoded to FM). Even that can be fixed with adding a different card. Then you just need the huge amplifiers to kick the signal up high enough for transmission to the antenna.
Yes, people in debt over their ears will sell you out - and so will people who aren't in debt.
Which is why they do a whole person investigation. Debt is only one of the factors. Fact is, most of the turncoats we've caught did it to hide secrets or get out of debt. There weren't many who sold out for money that weren't in financial difficulties. If I'm not swimming in debt, am I really going to risk lengthy prison sentences or even death for a few thousand dollars? I know criminals do it all the time - but we're not talking about known criminals here. We're talking about people with more or less clean records.... not really. How many innocent people have accepted plea-bargains rather than go through the time and expense of contesting stuff. A lot of people would be so intimidated by the whole situation that they'd just die of embarrassment.
We're talking adults here, not kids. A security clearance is a serious matter. Any surveillance is to be reported and investigated.
Now what would happen if that was followed up a few days later with a bogus lawsuit? And then someone talked to the guy, and said "look, this can all go away if you do xyz for us... - in return, you'll receive notification that she's some psycho bitch off her meds and the lawsuit will be dropped"... and make xyz something so small, so minor, that its worth it.
The moment you bring xyz up, I'll go to OSI and blab, they'll do their thing(and call the FBI, etc), and you'll be rolled up and sent to Gitmo.
At least partially, we're talking about personality types here. Anybody checking me out will quickly figure out that I'm an ornery bastard and trying to blackmail me with something, real or not, is going to get you reported. If I report it, and you're after classified, suddenly the fact that I'm in debt or cheating on my wife(or you're falsifying evidence that I am) is secondary to reeling you in.
Those who get into debt, have gambling problems, associate with certain groups, have marital problems, or secrets that the general public disapproves of(like being gay, liking to sniff schoolgirl shoes, whatever), you are MORE LIKELY to be compromised. We're talking probabilities here.
Yes, but planted blackmail such as this requires you to break into their home or steal/hack the device.
Then you would actually have to indicate to law enforcement that he had the illegal material. That he has no clue about, so you have to clue him in on before he'll believe you.
It's a lot more complicated than blackmailing a person with a real secret. Not to mention, like I said, an innocent person is a lot more likely to report the incident, confident that 'the truth will come out'.
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*Sigh* Why do so many make this assumption, slashdotters should take a few business/industrial engineering courses to understand it's not as easy as just selling another part. Everytime you add a part to your line-up it costs additional money and resources to manage it. Each part may need it's own substrate design, test programs, software support, etc. It also becomes more difficult to manage what you build in terms of inventory and factory loading.
I mostly agree, though I'd note that we're talking about the same chips. There wouldn't be a different substrate design, test program, etc... They're the same chips, just with some non-functional parts disabled.
There will be cases where there is enough difference between parts where it makes sense to create an additional offering (eg disable half for 32-core); but the assumption that a company would segment to each core isn't correct.
I agree, my initial thought for a 64 core die was 4 core increments, with a matching decrease in the reliance on core speed as a metric. 64-60-56, etc...
My rule of thumb is that most people won't notice the difference until the performance is affected by more than 10%. So by that logic, an 8 core difference should be maintained: 64-56-48-40-32. Have two speed levels, that's 10 chips in your lineup. Add in phasing between chipsets, you're up to 20-30, of which 10 or so could be handled with a couple guys in a warehouse for the legacy support customers. Phasing: Cutting Edge-Mainstream-Legacy. People pay through the nose for the fast 64, slightly less for the slow 64, the slow 32 is the 'bargain basement' chip, the fast 32 a slight uprate, etc...
The mainstream ends up buying wherever the bulk of the production is. If 56 cores on average survive, that's where the sweet spot will end up.
Wouldn't it make sense to sell any part that had at least one working core?
On the other hand, if we start seeing more than 8 cores, likely single core processors will pretty much be a thing to the past.
The yield of a 16 core processor with only 1 core functional is likely to be insignificant, to the point that it's not economic to try to sell them.
Let's say that 16 core processor is $320. That's $20 per core, so you'd likely only be able to get around $20 for the chip with one core operational. That's assuming you don't have to underprice them in order to get the economic crowd to not pay the extra $20 to almost double their performance*. Heck, there'd be a reason right there to bin them - They'll move up and buy a higher-profit duo-core instead.
At that point it might be cheaper to bin them, rather than to try to support chips that are less than 10% functional, and therefore likely to be hiding problems.
At $320, there'd still be quite a market for 4-8 core systems, hitting the sub $100 market, and the $150 market quite nicely.
*Don't forget that even for a bargain basement machine, $20 for increased performance wouldn't be much. You still have support components to consider. $400 for a '2 ghz' vs $420 for a '3.8 ghz' would have many bargain shoppers spending the extra $20, only the most penny-wise would buy the cheaper one.
Don't forget that they're usually trying to make chips that operate as fast as they can, they then test the chips to see what they can do and sell them at that rate.
When yields get *too* good, they wouldn't be able to move the number of 'premium' chips they can actually produce at the price point they want to sell them for. Then there's the huge 'economy' save a buck market that they want to sell to.
Solution: disable something, underclock it, sell it for cheap, so you can still get that 10X price for the uncrippled product.
Also bioshock as a game felt unfinished toward the end, the story was interesting for the first part of the game, but by the time you got to Andrew ryan things just seemed to get really weird, and then on your journey to fountain the story loses all cohesiveness really.
.gov is buying art, it should stay fairly conservative with it. It's supposed to be a bit stodgy.
How would this distract from it being art, allbeit rushed/unfinished art?
There are plenty of movies that start out good that finish horribly or rushed. Where they butcher the film in the editing room. Some books are like that, where you get the feeling that the auther went 'OMG - I've spent a year on this book' and promptly ties everything up in a two week writing splurge with minimal editing.
Personally, I feel that Bioshock, heck, even the old Space Quest and Hero's Quest type games have more artistic merit to them than some pieces of 'art' like the crucifix in urine*, or the sectioned out cow**. Of course, most of my objection to them is that the government paid for them with tax money. If a private buyer wanted it, great. I just think that if the
*And I don't even consider myself a Christian.
**Cool science though. It's just that it should be funded as such, not art.
More efficient is a possability, but I suspect that once you throw in the differential and CV joints you'll lose the weight and cost advantages.
True, but you're not going to loose that much power in a differential, and you might want to have CV joints anyways to keep the weight of the motors as sprung rather than unsprung weight.
A quick search says that a differential will be 94-97% efficient. From looking at different efficiency graphs, such as on this site, you can have percentage differences of greater than 5% between different electric motors, within their optimal power zones.
Personally, it sounds like something for a design team to look at. Don't forget that you'll most likely be looking at hub motors if you're going for direct wheel drive, they're less efficient than a similar power traditional motor with a shaft.
You might be able to figure all this out with a proper design team and simulations, but I wouldn't be surprised at all if they ended up building prototypes to test it out.
The acceleration is could be a big deal. That's based on the flat power curve of an electric motor and it's ability to operate from a standstill. While a gasoline engine is still slipping the clutch (or torque converter) to avoid stalling, the electric is applying 100% torque. The acceleration will probably be a selling feature in the U.S. There's a lot of misperception that electric cars will feel like driving a golf cart.
Agreed. Especially given that electric motors tend to be more efficient the larger they are, under powering the motor doesn't make much sense.
I can well imagine dealers having a demo car with the traction control shut off so they can demonstrate that the car can burn rubber. Because a lot of people don't realise that burning rubber means lost acceleration, there will probably be an aftermarket (legit or gray) for the firmware that lets you do that.
I don't doubt that, though I think that most people willing to change out their car's chips to 'increase performance' will quickly figure out that burning rubber is counterproductive for both fuel economy and acceleration rates. I wouldn't underestimate the knowledge of the average nascar loving hot-rodder. Not that they wouldn't think that spinning tires is cool, but that they'd know that it's not the best way towards acceleration and plan accordingly. Maybe with a switch turning traction control on or off.
On the other hand, go two motors down to the SIEMENS 1LH5118, and you have a 19.7HP continous rated motor that has 90.8 max ft-pounds of torque. Good job finding a site with more detailed specifications on electric motors, most sites only have the continous ratings. I especially like the power curves.
One thing this thread has done is get me to research electric motors a bit more, the number of types they have is staggering. Of course, when you think about it, the average car has at least two electric motors, likely more, and only one IC engine.
Then you figure all the electric tools, compressors, AC/Heating systems, washing machines, computer fans, etc... I wouldn't consider it outragous to find out that there's at least an order of magnitude more electric motors than IC ones. Of course, most of them are very small in comparison to a car engine.
There's dozens of different types, depending on whether it's going to be fed AC or DC, is intended for a constant torque or constant speed despite load, or variable. Whether it's going to be starting/stopping a lot, or hardly ever. Whether it can have a gradual start, or a sprint start.
Looking at the power curves, the electric motor has nearly 100% of it's torque available at a mere 400 rpm, while they don't even list torque for the gasoline engine until 1800 RPM. It ends at 3600 RPM. Meanwhile you find motors rated between 3500 and 10000 RPM. Combined with the low speed torque, an appropriate reduction gear might be able to eliminate the need for shifting. Going by the graphs(150-125), for efficiency sake you'd simply want 25mph correspond to ~2800 rpm. Then 75 mph would be ~8400 RPM, which is within standards. Well, for the MES 200-250, I'd peg 25mph at 2000 rpm, giving 75mph at 6000 rpm. You'd have plenty of overhead still with those motors. Efficiency above 90% for much of it.
obviously gas, makes more torque, electric makes more controllable torque. (for similar HP rating, with correct gear reduction for each)
Show me a reference that says that a gasoline engine of a given HP rating produces greater torque than an electric motor of the same HP rating. Especially across the range that an electric motor is capable of exerting that torque.
Electric motors generally crap all over gasoline engines when it comes to torque, especially at low RPM levels. If it wasn't for how lousy storage methods are for electricity, we'd have been using electric cars for years.
So I can buy that, if their not rated equivalently and you want a single accell (which is likely for a car) And your not so worried about efficiency (run electric out of it's rated torque you lose efficiency big time)
then their is something, you can under rate the electric motor, as long as you rate your supply (battery?) equivalent to the gas motor.
Indeed, we're looking for acceptable acceleration profiles. zero to sixty is one good measurement, but I'd look at 0-35 and 0-75 as well. We're not looking at drag strip performance, we're looking at 'The red light just turned green'.
Now, does it make some sense that an electric motor, capable of producing 3 times it's rated HP for something like two minutes would produce better acceleration curves than a gasoline engine with three times it's HP? At least in the 0-85mph range than street cars operate in?
If your driving habits are worse than average(towing, lots of steep hills), you could go for two to one. If you regularly go 100% throttle using a gasoline engine on hills in your area, you might go one for one, but then there's questions of whether you sized your gasoline engine right.
Batteries are normally rated by total energy storage - their ability to supply power is easily sufficient once you've budgeted enough to get yourself a decent range.
As for efficiency, electric motors have an efficiency curve much like computer power supplies. They're generally very efficient around 100%, less so at 50%, not very efficient at 10%. Efficiency would be indeed be absolutely lousy at 10x the rated power.
Thus why the 'rule of thumb' is limited to 3x - for one thing you can't go 10x for long, seconds at most. It does trade off some efficiency during acceleration for efficiency during cruising. The idea is that the extra 3% efficiency you gain during the 10 minutes cruising at a constant speed is worth the 50% loss of efficiency during 10 of the seconds spend getting to that speed.
With a controller set to 'efficiency', it wouldn't go over the motor's ratings under normal circumstances. Sure, it'll overdrive the motor if you stomp the acceleration pedal from something like 30mph until you hit 75-80 mph, but if you've sized it so that 100% is 'constant 75 mph on level terrain', you'll be just fine.
Basically, what redcane said.
You achieve similar road driving performance with a electric motor rated with 1/3 the HP of a gasoline engine.
Electric motors are rated under load at maximum sustained power. Gasoline ones are measured unloaded peak power. Thus, a '25 hp' electric motor can operate as a 100hp one for a short period of time. This time is limited by heat generation. A good controller will have a heat probe much like the sensors for CPUs today, and limit power before the heat is enough to cause damage. This can be extended out with active cooling, if necessary. The Tesla electric car motor has a fan, for example.
The vast majority of vehicles don't operate at anything near their peak level except for brief periods of time. For example, I still have ~ two thirds of my throttle to go in my four banger at 75 mph. So at max speed I'm operating at ~33%. Multiply by three, I'd be operating an electric motor ~100%, it's most efficient loading. I wouldn't be able to do 80 mph for long periods, but I'd still be able to pass other traffic.
If I live in hill or hot country, I might want to use a 1/2 figure instead. As is, I've been forced to downshift on some steep hills to maintain speed. In an electric vehicle - as long as the hill's short, I'll be fine. If it's a long climb, I might have to slow down.
But anyways, if you want references:
http://www.electroauto.com/catalog/dcmotors.shtml -
http://www.austinev.org/evalbum/motor.html
Sorry, can't find the 1/3 reference at the moment.
One engineering issue with this would be that the 100 hp motor* will tend to be cheaper, lighter, and more efficient than two or four individual motors. Remember, most cars on the road are only two wheel drive. With the slip differential, it's effectively 1 wheel drive(the tire with the worst traction gets the most HP).
So you have to look at the possibility that having a simple drive train can be more efficient than individual wheel drive.
Though given the efficiency scales, a two motor system could theoretically be more efficient at low power by not powering one of the motors. Though I imagine that you could do sort of the same thing with a larger motor by only powering part of it.
*This would produce a very fast accelerating electric vehicle. I've read that an electric motor with 1/3 the HP can give you equivalent performance to a gasoline engine. IE 30 HP electric = 90 HP gasoline.
I'd tend to say that you have more to worry about than electric cars. Most modern cars are far quieter today than they used to be. Engine noice is no longer significant.
An electric car at high speed is still going to emit a fair amount of noise. Modern gasoline and even diesel engines are very quiet even at low speeds.
For the motorcyclist's 'being noisy is safer', well, you still have to worry about deaf people, even half-deaf elderly who are running around in a relativly soundproofed car. With the radio turned up.
Russia will sell just about anything to anyone with enough cash, including blueprints, plans, and technology. China probably isn't that far behind technologically, honestly. Radar and EW systems are certainly the US's strong point, but it would be unwise to assume that technology that's 40+ years old is unattainable by other nations.
For that matter, there's no reason other than distrust to simply buy the satellite data from either Russia or China. I'm sure they spend the effort. After all, they both have active space programs.
Still, a stealth satellite or three could serve the purpose of making them spend the effort. The idea being that putting the stealth satellites up there makes Iran* spend proportionately** more effort tracking and avoiding them.
*Simply picked as an example, North Korea would work as well.
**While the satellites would cost more than the tracking, the US has so much greater resources that it'd still be a win for us. A $50k missile is cheaper for us than a $5k truck for most countries, proportionately.
The parent was talking about having the warranty service diagnosing hardware issues do it in a fashion independent upon what the customer has done to his HD.
By booting from your own drive, you eliminate any software issues, and can even have automatic access to any specialized diagnosis tools.
If the issue is suspected to be the HD, you plug it into a dedicated HD tester.
What you're suggesting adds a couple hundred to the cost of the system for little benefit. For the personal user, backing up data(always a good idea), then performing a wipe/reinstall is a good idea - to prevent data theft, if nothing else.
If your choice is a new HD, that's your choice, but new laptop HD's are expensive, especially if they're big.
Working for the government, I can do this even better.
The warrenties we get explicitly mention that they don't need the HD back to perform service.
We can even call them up, go 'We have a bad HD, send us a new one, and you're not getting the old one back' and they'll do it.
Well, they could get it back, but only after we've taken the HD apart and used a disc sander on the platters...
You want paranoid? We degauss it before using the disc sander...
Please remember my point - At least by a non-first world nation.
The United States counts as a first world nation. Iran might not be able to put forth the effort into tracking all these down.
Remember, it's not just the equipment, it's also the manpower to do the analysis.
You'd need to have radar systems to find the objects, followed up by telescopes to confirm the profile of the detected targets. And if you're going as low as a screwdriver, there's an awful lot of targets.
We have stealth aircraft, designed to be minimally observable to radar.
Couldn't we do the same for satellites?
Sure, planes have the advantage of being able to hide in the clutter, but surely there's enough debris up there now that a satellite with the radar profile of a wrench or bolt might not get noticed.
At least by a non-first world nation. And I'd include China in that list. Sure, they have problems, but they do have the resources to do quite a bit.
Then again, why bother? Said non-first world countries also lack the ability to shoot the satellites down, or even interfere with their operation.
It looks like you're trying to be funny, but car lights would actually be one of the lesser offenders. The big offenders would be street lights, of which there are many where there might be a car per hour. Heck, my little town has at least as many street lights as we do people, and our roads aren't even paved.
Besides that would be exterior offices/stores which never shut their lights off, even when they're closed at night(and keep their lot lit). Yes, I know, safety issue, but a motion sensor with a delay timer would work almost as well, and save large amounts of electricity. What I'm thinking of is a system which is like 'last motion' + 5 minutes.
You also have neon/billboard lighting, but in most areas that ends up being fairly minor compared to the others. Other than places like Los Vegas, of course.
Basically, we need to set up an automated system like the home energy saving - shut off the lights when you aren't in the room.
Besides consistency and learnability, using standard dlls can also reduce bloat - a program that tries to reimplement the wheel will be larger, and likely slower.
For one thing, a proper system dll, such as what's used to create standard windows and buttons should be highly error-checked, and therefore stable, not to mention highly optimized to make it faster.
A good 'lean and mean' program should make use of system dll files whenever it makes sense.
Take Media player classic versus windows media player. Both use external code to play their media. That's just fine.
From what I remember, 7 or 8 wasn't bad, then 9 was horrible, 10 is getting better(at least you can hide most of the crud), I haven't used 11.
The creaters of classic realize something important. People want to watch videos more than they want a fancy 'skin' that just gets in the way of playing videos.
For example, why should I dedicate as many pixels to the border and controls as I am the video? I might want to be doing something else with that screen space. And what's up with the majority of the controls being nonfunctional most of the time? Why do I have to hit ctrl-p to play/pause, instead of the nice big, easy to hit spacebar? Why did they shrink the seek bar, making it less accurate/easy to control, while not using the space gained for anything useful?
I'll frequently play a video in the corner of a screen while reading something else. When I'm doing that, I rarely need more controls than a play/pause button, and selecting the screen and hitting space works for that. The majority of the time, the only control visible with classic is the seek bar. It's a nice thin bar across the bottom that also tells me how far into the video I am, that I can easily adjust if I want to.
At least in XP, it's 68k.
Larger than I thought it was going to be.
Still, making a program work in widows takes some space.
And therein is the problem; because making a copy in RAM of a computer program, which is made as a necessary step in the execution of the program, constitutes Fair Dealing or otherwise does not infringe copyright.
Yes, but with enough lawyers and a slightly technophobic judge, you could get the argument of the parent.
Personally, I'd argue that a 'copy' exists in RAM as much as a 'copy' exists on the screen when you play a movie. The data is still stored on the media, whether it be a DVD, tape, or film.
Then there's the issue of the HD. The law actually allows you to make a backup of any software you purchase a license for. The lawyers managed to convince a judge/jury that the 'backup' is the copy installed on the HD, thus the copy in the RAM is an infringement.
Games are actually the most likely to get into trouble for something like this; their usage of 'copy protection' that requires the disc to be in the drive for operation and selective copying of files during installation would mean that you don't have a true backup.
They are using stem cells from placentas and umbilical cords, but at the time of birth they're almost like adult stem cells; they're no longer as plastic as earlier term stem cells.
Then there's the whole 'tarred brush' problem - current administrations don't make a huge differentiation between fetal stem cells and birth stem cells. There are also some ethical problems with using the discarded parts of a baby (cord&placenta) in research when the donor is a minor and unable to give consent. You'd think that the parents could give permission, but there are still issues for the really paranoid people.
One suggested source was fetuses that are generated yet discarded at fertility clinics*, not aborted fetuses/babies. That would result in absolutely 'fresh' cell masses, that by design are never going to be implanted to grow into a baby, that right now end up as medical waste.
*Fertility clinics will generally fertilize a half a dozen eggs or so at a time. They do this to increase the odds of getting a viable embryo. Remember, the whole reason somebody would go for artificial fertilization is because something is messed up so they can't do it the natural way, so the odds are good that any given fertilized egg won't be viable. The process is fairly expensive, yet collecting/fertilizing multiple eggs in a procedure doesn't really cost any more. So they do a number at once, select the most 'viable' embryo, and implant that one (or two).
Not much different than nature, really. The odds are slightly against any given fertilized egg surviving to the one month stage, when women usually start figuring out they're pregnant.
Simple enough; remove the Y chromosome and substitute a duplicate X.
Make sure you screen for some defeciences first though.
A good point; the ethical dilemmas of embryonic stem cell research has resulted in a comparative lack of funds.
Another argument would be that embryonic stem cell research is 'higher level' research - more theoretical than practical. The lessons learned there could filter down and help adult stem cell research develop practical treatments.
For one thing, without some extensive modification you'll have problems with immune systems rejecting the cells; just like with transplanted organs unless you make it a habit to collect them for all children. That's a rather massive storage project, and what happens if an accident takes out your tube of stem cells.
Better to use adult stem cells - they can be harvested anytime, and we can provide service to people today using them.
All the rest are software and peripherals.
Sure, my computer isn't currently ready to run a 50kw radio station broadcast.
However, throw some software on it and it can, as long as you don't expect it to be doing the modulations itself(IE output the sound to a board to be transcoded to FM). Even that can be fixed with adding a different card. Then you just need the huge amplifiers to kick the signal up high enough for transmission to the antenna.
Yes, people in debt over their ears will sell you out - and so will people who aren't in debt.
... not really. How many innocent people have accepted plea-bargains rather than go through the time and expense of contesting stuff. A lot of people would be so intimidated by the whole situation that they'd just die of embarrassment.
... - in return, you'll receive notification that she's some psycho bitch off her meds and the lawsuit will be dropped" ... and make xyz something so small, so minor, that its worth it.
Which is why they do a whole person investigation. Debt is only one of the factors. Fact is, most of the turncoats we've caught did it to hide secrets or get out of debt. There weren't many who sold out for money that weren't in financial difficulties. If I'm not swimming in debt, am I really going to risk lengthy prison sentences or even death for a few thousand dollars? I know criminals do it all the time - but we're not talking about known criminals here. We're talking about people with more or less clean records.
We're talking adults here, not kids. A security clearance is a serious matter. Any surveillance is to be reported and investigated.
Now what would happen if that was followed up a few days later with a bogus lawsuit? And then someone talked to the guy, and said "look, this can all go away if you do xyz for us
The moment you bring xyz up, I'll go to OSI and blab, they'll do their thing(and call the FBI, etc), and you'll be rolled up and sent to Gitmo.
At least partially, we're talking about personality types here. Anybody checking me out will quickly figure out that I'm an ornery bastard and trying to blackmail me with something, real or not, is going to get you reported. If I report it, and you're after classified, suddenly the fact that I'm in debt or cheating on my wife(or you're falsifying evidence that I am) is secondary to reeling you in.
Those who get into debt, have gambling problems, associate with certain groups, have marital problems, or secrets that the general public disapproves of(like being gay, liking to sniff schoolgirl shoes, whatever), you are MORE LIKELY to be compromised. We're talking probabilities here.
Yes, but planted blackmail such as this requires you to break into their home or steal/hack the device.
Then you would actually have to indicate to law enforcement that he had the illegal material. That he has no clue about, so you have to clue him in on before he'll believe you.
It's a lot more complicated than blackmailing a person with a real secret. Not to mention, like I said, an innocent person is a lot more likely to report the incident, confident that 'the truth will come out'.
Not sure, by any means, but more likely.