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Faulty Chips Might Just be 'Good Enough'

timothy posted more than 9 years ago | from the next-week-the-soda-ring-hammock dept.

Technology 342

Ritalin16 writes "According to a Wired.com article, 'Consumer electronics could be a whole lot cheaper if chip manufacturers stopped throwing out all their defective chips, according to a researcher at the University of Southern California. Chip manufacturing is currently very wasteful. Between 20 percent and 50 percent of a manufacturer's total production is tossed or recycled because the chips contain minor imperfections. Defects in just one of the millions of tiny gates on a processor can doom the entire chip. But USC professor Melvin Breuer believes the imperfections are often too small for humans to even notice, especially when the chips are to be used in video and sound applications.' But just in case you do end up with a dead chip, here is a guide to making a CPU keychain."

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342 comments

"Good Enough" (5, Funny)

Anonymous Coward | more than 9 years ago | (#11987744)

If ever a story was appropriate for Slashdot.

oh yes, by all means (5, Funny)

justins (80659) | more than 9 years ago | (#11987754)

Don't throw away those "almost perfect" CPUs! Give them to needy people in the third world!

So they can remark them and sell them back to us...

Re:oh yes, by all means (5, Funny)

Rosco P. Coltrane (209368) | more than 9 years ago | (#11987835)

Don't throw away those "almost perfect" CPUs! Give them to needy people in the third world!

I think you mean the 2.99999999th world...

Sounds like Radio Shack parts (5, Funny)

Mac Mini Enthusiast (869183) | more than 9 years ago | (#11987927)

Reminds of of the old joke about electronic compoment manufacturing fabs. They'll sort the parts coming off the assembly line into three bins, depending on how the testing of each part went :

Military Grade
Consumer Grade
Radio Shack

Re:Sounds like Radio Shack parts (0)

Anonymous Coward | more than 9 years ago | (#11987972)

Radio Shack

Boy, when you say "old joke" you mean it. Rat Shack selling parts, that's hilarious. Do you have any Heathkit S100 jokes?

Re:Sounds like Radio Shack parts (1)

Mac Mini Enthusiast (869183) | more than 9 years ago | (#11987994)

Do you have any Heathkit S100 jokes?

Haha, I wish ;-)

But seriously, you can still find some basic parts in most radio shacks : resistors, caps, pots, transistors, standard op-amps, basic TTL, etc. Unfortunately most of rat shack's sales are consumer products of shoddy quality and/or ripoff prices. But most other stores do have components hiding away in some corner.

Re:oh yes, by all means (5, Informative)

slughead (592713) | more than 9 years ago | (#11988045)

My friends work in a warehouse where they resell Compaq and HP parts to companies.

They mainly sell old stuff, almost all of it's used.

There's this company that they currently get most of their inventory from, let's call them company X.

Company X sells used parts too, they just do rigorous testing before they send them to customers, so a lot of it is marked "defective".

When company X marks something "defective", they pay to have it shipped to my friends' company. It's actually cheaper to do that than to recycle the parts, so my friends' company actually pays just a few dollars for a thousand pounds of equipment.

My friends personally go through all of the components, and put them through the extensive refurbishing process of blowing the dust off and inserting them into static bags.

They test it "good enough".. which entails making sure the computer boots up with that RAM and CPU. Maybe a 1 minute memory test on occasion. All in all, about 10% of everything they send out is worthless, and will be sent back by the customer in a week.

Already commonplace with RAM chips (5, Informative)

no parity (448151) | more than 9 years ago | (#11987755)

And for a long time so. "Audio RAM" is the euphemism.

Re:Already commonplace with RAM chips (4, Informative)

gl4ss (559668) | more than 9 years ago | (#11988089)

and in counterfeit ram ;)

don't forget that.

but the real reason for disposal i think is that throwing away at that early saves money from the manufacturers, like, it's much cheaper to throw away one chip than to throw away a tv that doesn't work good enough to be sold.

however.. what would be the good solution? maybe build the chips redundantly so that it wouldn't matter if one gate didn't work?

first (-1, Offtopic)

Anonymous Coward | more than 9 years ago | (#11987756)

firstness [bf]

Already being done... (5, Interesting)

leshert (40509) | more than 9 years ago | (#11987757)

If I remember correctly, digital answering machines use "reject" RAM chips that aren't suitable for data storage, because minor dropped bits in a recorded message aren't discernible.

Re:Already being done... (1)

toddestan (632714) | more than 9 years ago | (#11987818)

My guess is the few things defect chips are used in like digital answering machines don't come anywhere close to using up the supply out there. So most defective chips are still getting trashed/recycled.

Re:Already being done... (5, Funny)

Anonymous Coward | more than 9 years ago | (#11987840)

I'm u9ing on} in my com%ute! an; I havea't nHticed+any pro~lems.

Re:Already being done... (5, Interesting)

Ed Avis (5917) | more than 9 years ago | (#11987973)

If it's just RAM, and the defects are just the odd bad location here and there, then BadRAM [vanrein.org] could help. The main difficulty is getting the support loaded early enough, e.g. at installation time. DIMMs could have their own defect list and a way for the motherboard to query it.

Re:Already being done... (0)

Anonymous Coward | more than 9 years ago | (#11987916)

Not only digital answering machines - because of the way that chips are designed (at least at the last US chip manufacturer), it's possible for them to still be used for computer memory by disabling the portions of the chip that fail. That manufacturer sells those chips under a different brand name - and, in fact, also purchases "defective" chips from other manufacturers and relabels them, selling them on the spot market and in modules that go to tier two and white box builders. It's a running joke that the most expensive parts are the "defective" parts because they've been tested so many times!

i486 SX vs DX? (5, Interesting)

Mac Mini Enthusiast (869183) | more than 9 years ago | (#11987969)

Wasn't that the difference between the 486 SX and 486 DX, regarding the math coprocessor? Actually, I've heard two versions of the story. One is that the SX had the math coprocessor intentionally crippled by Intel, but sold for a cheaper price for larger volume sales.

The other version was that the coprocessor had the highest failure rating for the chip fabrication. So on these chips with a failed copressor, the coprocessor was turned off, but the rest of the chip was still usable.

I vaguely remember this whole practice was described in a computer book my friend was reading, because I remember a joke the author told about computer salesmen. Unfortunately I only remember the joke, not the useful info from that book. (This joke comes from the days of small computer shops)
Q : What's the difference between a computer salesman and a car salesman?
A : The car salesman knows when he's ripping you off.

Re:i486 SX vs DX? (5, Informative)

bulliver (774837) | more than 9 years ago | (#11988097)

I remembered reading something like that so I dug out an old book of mine, "Upgrading and Repairing PCs" by Scott Mueller (2000):

The 486SX chip is more a marketing quirk than new technology. Early versions of the 486SX chip actually were DX chips that showed defects in the math-coprocessor section. Instead of being scrapped, the chips were packaged with the FPU section disabled and sold as SX chips.

By the way... (-1, Offtopic)

Canadarcy (838270) | more than 9 years ago | (#11987761)

I've heard IE 7 is going to have bad CSS support...can anyone confirm?

Re:By the way... (0, Offtopic)

Ritalin16 (867772) | more than 9 years ago | (#11987775)

Yes, Microsoft decided not to support CSS2

Re:By the way... (0)

Anonymous Coward | more than 9 years ago | (#11987889)

What?! You're kidding me right?

Re:By the way... (0)

Anonymous Coward | more than 9 years ago | (#11987991)

You think that's important?
Well, I heard that IE7 is going to have bad CSS2 support.
Someone should put that on Slashdot rather than this nonsense about chips or something.

Bug hunt (1)

otter42 (190544) | more than 9 years ago | (#11987767)

As much as I applaud the decision to save the environment, would this not cause problems for things such as bughunts? Would they sell two tiers of chips, those for developers, and those for consumers?

I know thats what major chip manufactors do now. (1)

Prophetic_Truth (822032) | more than 9 years ago | (#11987768)

They create a batch of processors; from that batch they test a percentage for speed. Some batches perform better than others and get higher ratings. Sometimes your batches are all really good, but the market requires something cheaper, so you underclock some good processors and sell them for a lower price.

No Thank You. (5, Insightful)

Anonymous Coward | more than 9 years ago | (#11987781)

I'd rather my chip works as advertised.

Re:No Thank You. (0)

Anonymous Coward | more than 9 years ago | (#11988065)

> I'd rather my chip works as advertised.

In spite of the 'insightful' mod, this isn't; it verges on tautology.

Are they going to blatantly lie in their advertising? No? Then the chip will "work as advertised".

What you probably want is a chip that meets the original spec; fair enough, but if the lesser chips are sold as meeting a *lower* spec, it's not false advertising.

Of course, most advertising is vapid and has little to do with the real spec anyway. They'll weasel a way round the issue if they have to. But there's NOTHING wrong in principle with selling these lesser chips as long as people realise what they're getting.

Anyway, back to your point. I doubt either of us would be happy with a flakey P4 or Athlon; but are you really that bothered about a couple of faulty bytes on your answerphone's memory?

Re:No Thank You. (4, Insightful)

js7a (579872) | more than 9 years ago | (#11988078)

The problem is that there is essentially no way to write a regression test that checks the operation for any permutation of states. Electrical problems with chip lithography, when they arise, are often dependent on a particular problem of indeterminate rarity.

If a CPU producer passed a general purpose chip, and it ended up that the defect was responsible for a tort, then they might be liable.

Their ought to be three bins: MIL-SPEC, No Defects, and Defect Detected But Passed Regression Suite. Anyone purchasing from the third bin has to accept liability for unforseen malfunctions.

Low cost solutions for the Military (5, Funny)

Anonymous Coward | more than 9 years ago | (#11987783)

Actually, the supercomputers used for warfare and conflict analysis at the Pentegon and the CIA use these rejected chips.

In addition, they are used in the so-call "Star Wars" missle defense system prototype.

Although these chips don't actually work, the results are often good enough for their purposes.

Chipmakers aren't environalists are they? (0)

Anonymous Coward | more than 9 years ago | (#11987794)

Chipmakers aren't environalists are they? Is that how you spell environmentalist?

I'm not so sure... (4, Insightful)

Bigthecat (678093) | more than 9 years ago | (#11987797)

Considering the amount of defective products that make it into our hands already after this 'quality assurance' for various reasons, I'm not sure adding more that already have a defect, however minor, is such a brilliant move.

It may seem that there's a basic linear line between over-the-top quality control and cost and more economical quality control and cost, however one has to think that if it turns out that these chips are more likely to have defects in them and in fact do in the future, how long will costs remain low? The chip will still be useless and will have to be replaced, added to that the cost of making the returns from the customer/store and then the possible customer dissatisfaction with the company's quality which could result in a lost sale in the future. Will it actually be cheaper in the long term?

I'm not so sure...Expiration Date. (0)

Anonymous Coward | more than 9 years ago | (#11987831)

Just wait till we start applying the "Good enough for cheaper goods" philosophy to food.

Re:I'm not so sure...Expiration Date. (0)

Anonymous Coward | more than 9 years ago | (#11987894)

"Eat recycled food. For a happier, healthier life. Be kind and peaceful to each other. Eat recycled food. Recycled food. It's good for the environment and okay for you."

Re:I'm not so sure... (5, Insightful)

mjh49746 (807327) | more than 9 years ago | (#11987957)

I'll have to agree. I've just RMA'd a DVD burner a day after I got it back from the last RMA. Not to mention having to RMA a stick of RAM not three months ago. QA seems to be a really sad joke, these days.

We've already got enough bad components floating around. We surely don't need any more.

Re:I'm not so sure... (1)

BHearsum (325814) | more than 9 years ago | (#11988057)

Totally not unusual. We get bad batches of various computers parts every week. Often, it is generic ram. Lately, LG has switched manufacturers, and their DVD burners have gone to shit. When we get a bad batch, 90% of it gets RMA'ed. I'm just glad that most of it is used inhouse instead of customers getting it and returning it.

I'd rather have... (-1, Offtopic)

bogaboga (793279) | more than 9 years ago | (#11987801)

...a comprehensive howto on how one can get and maintain clear-crisp fonts on Linux as the default fonts on my SuSE 9.2 are blurry. And now, my Konqueror, (the latest and greatest sofar), cannot maintain toolbars where I place them! What the hell...

go figure (1)

KaiSeun (786953) | more than 9 years ago | (#11987803)

This story has been updated to note that Melvin Breuer's research was supported by the chip industry

Looks like this is the excuse the industry has been wanting in order to justify selling shoddy parts. Of course, doesn't this happen already? I may be cynical, but doesn't any consumer expect their product to be free of defects (or at least what they deem accepetable).

If small faults are tolerable (4, Insightful)

BillsPetMonkey (654200) | more than 9 years ago | (#11987804)

Then why not have analogue processors instead of digital processors. Seriously - they're much faster than digital switches.

The only reason for moving to digital switches was accuracy - the cost of the first digital bitflipper processors was far more expensive than valve technology was in 1950s and 1960s. And that really was the only reason for changing to digital processors.

Re:If small faults are tolerable (0)

Anonymous Coward | more than 9 years ago | (#11987919)

Um, aren't digital processors also a whole lot easier to produce than analog? I mean... we've got this whole fabrication industry that's built around digital components. We can't just change over to analog without redesigning the whole fabrication process, right?

I've never learned about analogue processors... are there any working prototypes/examples? Sounds kinda cool.

Not quite (5, Interesting)

beldraen (94534) | more than 9 years ago | (#11987935)

While I agree that analog processors probably hold some promise, there is one large issue with them: heat. A major reason why processors get hot in the first place is that after each cycle the state is returned to a neutral position, which usually means grounding the gates to discharge them. This waste energy has a large conversion over to heat. Analog processors can really be thought of digital with multiple states, instead of two. This means that while more work can be done, there is larger values of charge to disapate.

What has always had my curiousity for why it has not been seemly worked on is "reversable" chips. There are essentially two sets for every mechanism and the system toggles back and forth. The discharge of the old system is used to drive the new mechanism; thus, a lot of wasted discharge is conserved for reuse. Reversable chips are reported to generate far, far less heat. I have heard that Intel and others know about this, but it is simply a better immediate investment because consumers are happy paying for the current line of toasters.

GFir5t (-1, Troll)

Anonymous Coward | more than 9 years ago | (#11987813)

Thesn3 early

Finally, a way... (1)

Anonymous Coward | more than 9 years ago | (#11987816)

...for Dell to make even shittier machines than they do now. I could see them putting out an entire line of machines based on 'good enough' CPUs. They could call it "Sloptiplex."

Nothing new (5, Insightful)

Rosco P. Coltrane (209368) | more than 9 years ago | (#11987817)

LCD manufacturers routinely put defective screens on the market, on the premise that a dead pixel here or there "won't be noticed". Too bad, because consumers do notice and do tend to return the product equipped with the dodgy screen, only to be told that it's "normal".

In short: computers suck...

Re:Nothing new (0)

Anonymous Coward | more than 9 years ago | (#11987878)

Didn't Toshiba or possibly Sony commit to never shipping notebooks with dead pixels just recently?

Re:Nothing new (1)

cfavader (754724) | more than 9 years ago | (#11987913)

Actually this happened to a friend of mine just a few weeks ago. He complained enough and got a new one, only to find that one had a dead pixel right in the middle of the screen as well. He returned this one and the same thing resulted. This went on for awhile until he finally got a fully working one and a refund.

Now obviously this doesn't always happen, but it certainly wasn't cost effective for them in this case.

Caveats (2, Informative)

karvind (833059) | more than 9 years ago | (#11987819)

Testing ICs is an exponentially hard problem these days. One-third of the cost is devoted to it. Thus it may be a good idea to test the chip for only the applications it is needed (in some restrictive environments) and if it passes, it can still be deployed. It will ease some of the economic hammer on the manufacturing these days.

Xilinx offer EasyPath [xilinx.com] option by testing for a customer-specific application. Customers use EasyPath customer specific FPGAs to achieve lower unit costs for volume production once they know their design is fixed and no longer requires the full programmability of an FPGA.

Already being done (somewhat) (5, Insightful)

SA Stevens (862201) | more than 9 years ago | (#11987820)

The CPU vendors are already doing a 'sort and grade' operation, when they label processors. Have been for years. When the yield from the fab is lower-grade, the dies get packaged and labelled as lower-speed parts.

Then the Overclockers come in and ramp the speed back up, and claim 'the faster chips are a ripoff' and complain that 'Windows is always crashing.'

Re:Already being done (somewhat) (1, Insightful)

Rosco P. Coltrane (209368) | more than 9 years ago | (#11987858)

Then the Overclockers come in and ramp the speed back up, and claim 'the faster chips are a ripoff' and complain that 'Windows is always crashing.'

Perhaps it's because Windows also tends to crash on normal machines too? I mean, you never hear *nix overclockers complain that their OS crashes all the time do you?

Re:Already being done (somewhat) (0)

mattyrobinson69 (751521) | more than 9 years ago | (#11987989)

i installed nvclock from portage and as a test clocked my graphics card as high as it would go, no immediate errors so i set it to overclock on startup.

Ive still not found any more crashes than before (i had to try kde 3.4 beta's, which crashed a couple of times). i haven't seen a noticable speed increase but i might as well leave it as it is incase i do come round to using my gpu to its fullest one day.

Re:Already being done (somewhat) (5, Insightful)

taniwha (70410) | more than 9 years ago | (#11988073)

(I'm a sometimes chip architect, so some background) - there's two sorts of tests that go on when you fab chips - functionality (do they do the right thing, are all the gates working, are all the wires connected) and speed (does it go fast enough).

For most chips, except ones like CPUs where you can charge a premium you don't speed bin (it costs lots of money), you pick a speed you think it should go at and toss the rest. Shipping chips that almost work is bad business - think about it, I make a $5 chip it gets put in a $100 product, if 10% of my chips don't work my customer loses $100 for every $50 he pays me, I have to get my failure rate down so it's in the noise as far as the customers are concerned, otherwise they'll go to the competition.

I think that the number of applications the original article's talking about where chip errors are tollerable are pretty small, suppose my CPU has a bit error in the LSB of the integer adder, the IRS may not care if my taxes are off by 1c, but the MSB is a different matter ("sir you appear to owe us 40M$"). On the other hand an LSB error is a big deal if the value you are dealing with is a memory pointer and breaks a program just as badly as if it is the MSB.

Finally a word about "metastability" - all chips with more than one clock (video cards are great examples" have to move signals between clock domains - this means that signals can be sampled wrongly (well designed logic should handle this) or in rare cases suffer metastability where the result causes unstable logic values to be latched into flops (usually these look like a value that swings wildly between 0 and 1 at a freq much higher the normal clock, a flop in a metastable state can 'pollute' other flops downstream from it turning a chip into a gibbering wreck. Now well designed logic doesn't do this very often, the flops chosen for crossing clock domains are often special anti-metastability flops used not for their speed or their size but their robustness - but the physics of the situation means that it's simply not possible to avoid - just possible to make it not happen very often. What you do need to do is figure out how often something will fail and pick a MTBF that is appropriate for your device ... I once found myself discussing this issue around a video chip we were designing and basically what it came down to was comparing the theoretical worst case failure rate (chip people tend to be very conservative, keeps us on the right side of Murphy) of our chip with Windows - our chip might fail once a year (and even then there was a pretty good chance you wouldn't notice it) while back then windows blue screen every day - would anyone notice? nope

Micron has done this for years with RAM (5, Interesting)

Anonymous Coward | more than 9 years ago | (#11987832)

Micron started a group over 15 years ago that tests RAM chips at all stages of production that fails testing.

When I worked there it was called the "Partials Division". This group invented the "audio ram" market. They have a wide ranging sorting and grading process. It is called "SpecTek" I believe now. I sometimes see low end memory modules with SpecTek Ram.
12 years ago, I was production technician in a Surface Mount Assembly division that shared a building with Partials. We used to assemble memory modules and even video cards that used "PC grade" chips from the partials group. Everyone said they were good enough, but personally I have always steered clear of them.
The last year I was at Micron, we had a lot of discussions with NEC, Intel and some Russian Fabs to provide the same services to them. We tested a couple million chips from these companies in tests. Never did hear what the end result was.

they don't waste finished chips (5, Insightful)

seanadams.com (463190) | more than 9 years ago | (#11987842)

Many of the chips fail inspection prior to going into the package, and then some more fail functional test after that. Probably more than half the price of a chip is the factory itself and the R&D work which is amortized over so many zillions of parts, and much of the rest is all the handling, packaging, shipping, and middlemen. I'd guess less than 10% is per-part materials and labor.

Therefor throwing away a $2 chip during production doesn't cost $2. It's only worth $2 by the time the customer pays for it.

Sure you could sell the defects at some discount, but it's only worth the trouble for some high volume part like RAM where defects are easily useable, and definitely NOT a part where the impact of some particular defect in the end user's application could be really hard to characterize (like a CPU).

the FUTURE (5, Interesting)

k4_pacific (736911) | more than 9 years ago | (#11987844)

In the FUTURE, single core processors will be dual core processors where one side didn't pass quality control. Someone will eventually figure out how to hack the chip to use both halves anyways, and the market will be flooded with cheap dual core chips that don't always work. Remember, you read it here first.

Re:the FUTURE - you are so wrong about technology (0)

Anonymous Coward | more than 9 years ago | (#11987948)

you do not know how disabling works

you are correct that motorola disabled FPU on 68xxx chips and sold them without fpu and sold non disabled chips at premium

you are correct that intel disables debugging hooks on intel chips and sells non disabled chips at premium

you are coorect that memory chips have disabled fields

you are corrrect to imply that non MP chips are sometimes crippled versions of MP chips. MP chips like titanic (titanium) are, by legal edict made to trade partners, illegal to disable MP features electronically, but other MP capable chips have been crippled and sold into uni-cpu channels.

but you do not know SHIT about how disabling works.. electronically gates are blown and cannot be repaired

no technology exists to repair these blown microfuse-like circuits

you are correct that dual chips will be tested and failures dropped, but the cores will be designed to fanout to only a single cpu package. they will not mount it in a dual package

for your prediction to be true (and it is not), the number of cpus would have to approach 8 or 16 cpus destined for a single package with only one or two disabled

the market would not stand for it, so the chips would actually be designed as 10 cpus of which 8 are left intact or 18 cpus of which 16 are not electronically disabled. but in that scenario the wiring would only go to 8 or 16 remaining cpus with no way to enable dead ones and no way to access the lines.

you are an idiot basically.

Re:the FUTURE (5, Interesting)

ltbarcly (398259) | more than 9 years ago | (#11987961)

Probably. But only for one revision, then they'll stop it. This has been going on forever. The 486sx was identical to the dx early on, except the FPU was disabled. I have never heard of a hack to get around this. Video chips are the same story, a radeon 9500 IS a 9700, with half the pixel paths disabled usually due to defect. You can get around this in software even.

Here is where you can make out like a bandit. Buy up a bunch of the revision which is hackable. Then, hack the ones you can and sell them as such. Then wait until supplies run out, and sell the ones where the hack failed on ebay. People will be on the lookout for the hackable version, and will pay a premium to get it from you. Oh, don't mention that you already tried it and it didn't work. They get exactly what they paid for, so this isn't dishonest in the least.

Actually, this happened to me. I wanted the Radeon 9500 with the ram in an L configuration, because you can soft-upgrade it to a 9700 most of the time. I bought one on ebay since there were no more on newegg. I specifically asked the guy "L shaped ram" he says yes. I get it and everything seems fine. UNTIL I lift off the heatsink. There, instead of a thermal pad or tape, is silver thermal compound. Clearly he had lifted the heatsink, and then put it back on when the hack failed. At least he was nice enough not to leave the hosed heat-tape on there. I ended up with a good upgrade for about what the newer revision would have cost anyway.

Now, in the next revision they just update the manufacturing to make it impossible to do the hack, because it is a nightmare for them to support all the half busted products that have been 'fixed' (even if they just say no, receiving and testing those products for the hack, and even phone support, costs like a bastard), and it cuts into the sales of the top tier products, where they make the highest margin. For chip companies this is as easy as dinging the faulty side of the chip before they assemble it completely, or putting some sort of "fuse" on the silicon itself, which they then burn out if that side is faulty. There is no way to take apart a chip to work directly on the silicon, and if there is and someone actually does it it will be a "Prove you can" since the equipment will be in the millions. (I can imagine a physics grad student with access to the machinery if they are doing superconductor or quantum computing research)

Re:the FUTURE (0)

Anonymous Coward | more than 9 years ago | (#11988144)

In the FUTURE, single core processors will be dual core processors where one side didn't pass quality control. Someone will eventually figure out how to hack the chip to use both halves anyways, and the market will be flooded with cheap dual core chips that don't always work.

Brilliant! Will we be able to destroy the circuit that disables the second core by drilling a hole through the chip, like they did with the Intel 486SX [ic.ac.uk] ? (cough!)

Processors? Or RAM? (5, Funny)

Transcendent (204992) | more than 9 years ago | (#11987849)

I can see it for RAM, but for processors, I don't think so.

Though, you would probably have to make sure that certian important data for an audio or video clip are stored in *good* memory. Or else you could run into problems where a clip doesn't know where to end.

But, what are the odds that a null terminator gets messed up in meao90efghijklmnopqrstuvwxyz{|}~ÇüéâäàåçêëèïîìÄÅÉæ ÆôöòûùÿÖÜ£¥áíóúñÑß±÷ !"#$%&'()*+,-./0Welcome to BankOne Online banking service! Your updated credit card number is 41
<<ERROR: Unexpected EOF >>

Not a good idea (5, Interesting)

IversenX (713302) | more than 9 years ago | (#11987851)

There is a reason for throwing out those chips! Maybe it's true that _most_ human ears wont notice that the least significant bit has been flipped in a über-noisy phone recording for a digital answering machine, but what if it was the most significant? That would make an audible "pop".

Ok, so maybe for non-critical equipment in the "use-and-throwaway" category. But this will not bring us cheaper hardware, just less functional hardware. Those chips are _literally_ going nowhere slow.

If you've ever had to debug something that turned out to be flaky hardware, you KNOW it's a PITA. If anything, awareness should be increased when it comes to the really cheap brands. They aren't always very stable, but people sometimes go for the cheapest RAM anyway, and then complain to ME when it doesn't work. There actually is some connection between what you pay, and what you get. Argh.

I'm done rambling now, thanks for waiting..

Re:Not a good idea (0)

Anonymous Coward | more than 9 years ago | (#11988141)

There is a reason for throwing out those chips! Maybe it's true that _most_ human ears wont notice that the least significant bit has been flipped in a über-noisy phone recording for a digital answering machine, but what if it was the most significant? That would make an audible "pop".

First of all, people used to listen to records all the time where there were audible pops, and it didn't make their heads explode or anything.

Second, even if all the bits of the sample are wrong, an answering machine probably samples at 8k Hz. If one sample has the wrong value, then the pop will be 0.125 milliseconds long, so not really that bad.

Third of all, these answering machines are already such low fidelity devices, that while the distortion may in fact be audible, there is all kinds of other audible distortion that's probably much worse. Have you ever looked at the speaker on one of those things? It's not exactly a hi-fi component, and it's probably driven way past its true capacity to play without huge amounts of harmonic distortion. In fact, if it's anything like the speaker on my cell phone or home phone, it's probably driven so hard that the cone hits its maximum excursion, which means it sounds like CRAP.

So basically, yes, this will probably truly add distortion that could be audible. But the product is already so bad when it comes to fidelity, that it's not getting much worse. It'd be like putting an ignition system that misfires once a week on a beat up old car that already doesn't run so hot. Yes, it might make it infintessimally worse, but in practice, it doesn't make much difference.

Faulty Chips (2, Informative)

p0rnking (255997) | more than 9 years ago | (#11987854)

I'm sure I read something, a long long time ago, that mentioned that Celerons were "faulty" versions of the Pentiums (and a comparison was made that the Durons were made as Durons, and weren't chips that were taken out of the garbage bins)

Re:Faulty Chips (4, Informative)

Anonymous Coward | more than 9 years ago | (#11987918)

A Celeron was a Pentium III with a part of bad cache. The half with the bad section was marked as such, which is why the Celeron always had half the cache of a P3. They also ran them as much slower bus/core speeds. I'm not sure what the newer "P4" celerons are though. Probably the same deal.

Re:Faulty Chips (0)

Anonymous Coward | more than 9 years ago | (#11987947)

Uh, no.

Celerons are Pentiums without as much Cache. Since Cache is the thing which makes a P4 not suck SO terribly bad, that means a Celeron is a REALLY shitty chip.

Re:Faulty Chips (1)

TLLOTS (827806) | more than 9 years ago | (#11987962)

That's true to an extent. What often happens with Celerons is that during testing for a normal P4 chip, if some of the cache in one bank is discovered to be faulty, then they disable that bank, reducing the cache to a level equal to that of a normal Celeron. However that doesn't mean that all Celerons are defective P4's. Intel will produce as many Celerons as neccesary to meet demand, so if demand outstrips the number of defective P4 chips then they'll simply disable a perfectly functional set of cache on a P4, label it a celeron and ship it out the door. So while some Celerons may indeed be faulty, they've had those faulty parts disabled so it will have no effect. Any part of a CPU being faulty would be extremely bad, as one wrong bit could screw things up majorly, so they're not about to be tolerated.

Do we forget so quickly? (1)

Oriumpor (446718) | more than 9 years ago | (#11987967)

The AMD XP to MP 2100 [livepublishing.co.uk] mod.

Now, in reality Celerons have a lower cache, lower bus speed and overall lower clockspeed. As I remember, because of this the core doesn't have to pass as high a standard as the current Pentium offering.

I'm sure there are others who would offer better knowledge on this.

Ati and nvidia do this already... (3, Informative)

mobiux (118006) | more than 9 years ago | (#11987855)

Usually thier LE and SE models have certain branches and pipelines already disabled. Usually these disabled pipelines are damaged in some way.

Lack of specification makes this hard to implement (1)

mpoulton (689851) | more than 9 years ago | (#11987874)

The manufacturing process errors that cause parts to be rejected vary greatly from part to part -- they don't all fail in the same ways. Additionally, some defects are acceptable for some applications and not others. It would require a great deal of time and effort to identify the exact nature and extent of each defect found in each part, and then to match that particular part to an application that will tolerate its fault. While it is conceivably possible, it would be very difficult to implement this sort of system. The only real exception here is for memory devices in applications that are universally fault tolerant (media). Processors and other devices do not lend themselves well to this because of the wide variety of fault types.

OK until code is mixed with the data (4, Interesting)

G4from128k (686170) | more than 9 years ago | (#11987890)

Apart from some hard-wired devices (simple sound clip recorders) or downclocked low-end devices, I don't see how defective chips can be used. The article suggests that the occasional error is OK for audio and video, but how do you ensure that the faulty chip never has to handle code, memory pointers, configuration files, hashes, passwords, encrypted data, or compressed data. I suspect that modern-day audio and video datastreams are becoming more fragile as they carry more metadata, highly compressed data, DRM, software, etc.

Something tells me that the manufacturers that use semi-defective chips are going to lose all their savings on product returns, warranty costs, and technical support. Given the low cost of most consumer electronics chips and the high cost of service labor, I doubt they will want the hassles of unreliable products.

If'n it were possible... (4, Insightful)

TheSHAD0W (258774) | more than 9 years ago | (#11987915)

...They'd already be doing it.

Please remember that this is the same industry that came up with the 80486SX when they were having lousy yields on 80486DX chips. If these processors had any utility, trust me, they'd find a way to make money off 'em.

Keychain (1)

ztirffritz (754606) | more than 9 years ago | (#11987925)

Apparently the overclockersclub stressed there server too much. Now I'll never know how to make a keychain out of CPUs...

Keychains, eh? (1)

cfavader (754724) | more than 9 years ago | (#11987930)

Damn, I wish I hadn't wasted all those old processors by scrubbing gum out of my carpet and then throwing them out, I could have used them to make perfectly useful key chains...

I dont trust (1)

OAB_X (818333) | more than 9 years ago | (#11987931)

A "deffective" chip to do my taxes thanks. Home tax software will only increase in popularity. Stuff like adding numbers matters. Thats a "mission critical" piece of software there, not to mention these chips would be useless to any distributed computing project or databases or work in Excel for example.

Bad idea.

Who could... (funny) (1)

chris_eineke (634570) | more than 9 years ago | (#11987932)

Who could resist broken chips? Especially the silicon-flavoured?
Condense them into a big clump on a plate, and I will megaherzedly dig into them while watching penguins fly through my broken windows. You just gotta love those intelligent clusters of beowulf penguins!

Ah! My God!

Too many embedded links to geeky stuff.

Pricing Structure Change (1)

eander315 (448340) | more than 9 years ago | (#11987937)

Intel, AMD, and other chip manufacturers must make a premium for their high-end chips to make a profit. They discontinue a speed grade once it hits a certain price point because it's not profitable to sell them that cheaply. I seriously doubt they're going to want to release even lower-margin, bargain chips that further undercut their more profitable high-end chips.

Good enough? (1)

hunterx11 (778171) | more than 9 years ago | (#11987949)

At least Intel didn't tell us that the Pentium was "good enough" with its floating point division error (even though it actually was 99.999% of the time).

Sinclair (0)

Anonymous Coward | more than 9 years ago | (#11987950)

Clive sinclair did this with transistors.
TI used to have the driveway to their offices composed from very out of spec transistors. Clive got a digger to dig up a few tons, had them sent to England. His staff then graded them into a,b,c (I think) and they were resold to hobbyists or used in his early amplifiers.
I read about this in the book 'clive sinclair and the sunset technolog'
He also used half working 32k ram chips as 16k ones in the zx spectrum.

USC Idiots! (0)

Anonymous Coward | more than 9 years ago | (#11987956)

We have a difficult enough job getting machines to do what we want, without pseudo-academics like this giving manufacturers yet another excuse to compromise on quality.

Once bad chips are allowed out the door, it can be difficult to know where and how they'll be used.

NASA for example, has a whole team of engineers scouring eBay and other outlets, just to find vintage electronic parts for the Space Shuttle program!

http://www.computerworld.com/hardwaretopics/hardwa re/story/0,10801,71140,00.html [computerworld.com]

If a 2000-styled election cliffhanger happens again, perhaps we'll have USC to thank for it.

Re:USC Idiots! (1)

standards (461431) | more than 9 years ago | (#11988101)

If a 2000-styled election cliffhanger happens again, perhaps we'll have USC to thank for it.

Gee, sounds like you flunked out of USC.

In any case, the idea isn't to put non-working components in your home computer. Instead, the goal is to use some rejected components for other uses where they can still succeed.

A good example is your favorite HDD. Does it have bit errors? Yep! But can you tell? Nope! Because the supporting hardware is able to detect and correct the errors without you ever knowing about it.

So why not apply the same principles to other computer components? The short answer is cost. It costs money to build more fault-tolerant devices. But the paper advocates reducing the costs of such fault-tolerance, and using the 2nd class componentry only where one can.

Learn to RTFA, and maybe USC will take you back!

Stories (2, Interesting)

MagicDude (727944) | more than 9 years ago | (#11987965)

Reminds me of a story I heard from my high school physics teacher. He had a friend in the military doing electronics. One big part of his job was to measure resistors because military specifications required that devices have a very strict tollerance. They wouldn't use anything which was more than 1% outside of specs, and they would simply throw out the rest of the resistors they bought. So my teacher's friend would simply take all these resistors to which he had accurately measured the resistances, and sold them to the local radio shack, since they liked being able to buy resistors that were within like 2-3% of the indicated resistance (I'm not an electrician, but I believe 5% or so is considered an acceptable tollerance for general applications?), and they got them cheap, and the guy made some money since his investment was 0, since as far as the military was concerned, he was simply selling trash. Couldn't something like this be done with chips, isn't there some market for chips that are 99.9% good?

Re:Stories (5, Insightful)

bbrack (842686) | more than 9 years ago | (#11988029)

If you go and buy a handful of 5% resistors, you will find ~0 that are within 2% of their value - if you buy 2%, none w/in 1%, etc...

Manufacturers are VERY aware they can charge a larger premium for better parts

Mr Researcher... (1)

bbrack (842686) | more than 9 years ago | (#11987988)

Would you really want to fly into airspace where the servers in the air traffic control centers are run by processors that are good enough...

Or bank with a bank whose data center processors are good enough...

While we're at it, let's get rid of process/product qualification - this could save thousands of parts for each digital chip out there. We could also get rid of burn in and any kind of stress testing, since we obviously wouldn't care if we had any parts out there that were 'walking wounded'

Hell, we could even get rid of any kind of functional test...

Seriously it's already difficult enough to test and get reasonable levels of coverage on current processors already - if the chips are going to be used in ANY kind of mission critical applications (or even in my home PC) I want a chip that is as good as current test processes can guarantee it to be.

How irritating would it be to have a processor with a hard fault in that caused errors on excercising a certain block of logic.

People have already mentioned that quite a few products already use defective ram chips, and engineers desigining various products are aware that parts like these are available, and are (or should) be using them where ever possible to reduce cost.

It might be interesting to go through some analysis to see if the increase in DPPM (and subsequent increase in returns) would be low enough to not completely cancel out the gains you would get from increased yields.

String him up by his balls... (1)

msimm (580077) | more than 9 years ago | (#11987992)

Really. Do we need more defective products being sold under the pretense that its ok.

Love the updated notice?
This story has been updated to note that Melvin Breuer's research was supported by the chip industry.
Slashdot, you care to update yours to refelect this minor detail or do you just like playing along?

This is completely bogus. (5, Insightful)

david.given (6740) | more than 9 years ago | (#11988002)

And anybody who actually knew anything about computers would know this. TFA doesn't mention what this guy is a professor of --- I bet it's not electronics.

Basically, the problem is this. With mechanical and analogue devices, most of the time you know that if you change the inputs a small amount, the outputs will change a small amount.

But digital devices are chaotic. Change one bit in the input, and the output is likely to be radically different. One bit in the wrong place on a Windows system can make the difference between Counterstrike and a BSOD.

You can use substandard devices for some applications; dodgy RAM, for example, can be used to store audio on, and it would work just as well for video framebuffers. But you could never put anything programmatic on it; that has to be perfect.

(IIRC, they do recycle faulty wafers. One of the ways is to scrape the doped layer off and turn them into solar cells. I don't know if they can use them again for ICs, though.)

Re:This is completely bogus. (1)

Have Blue (616) | more than 9 years ago | (#11988125)

Digital devices are the exact opposite of chaotic- they are deterministic. The rest of your post is correct, but that's the real reason why a tiny error somewhere in the billions of RAM bits can be picked up, propagated, and use to corrupt the rest of the system.

This is also a problem in medicine (5, Insightful)

Glowing Fish (155236) | more than 9 years ago | (#11988033)

If you look at what the "big ticket" items are in the US economy, electronics and medicine are up at the top of the list.
And the reason for this is, as you get closer to perfection, it takes more and more of an economic cost, in terms of money or resources or time or effort. For a computer or a medicine to go from 90 percent to 99 percent utility means a ten fold increase in price.
Thats why the constant quest to have "perfect" electronics and medicine is driving up the prices of these things to the point where normal people can't afford them. If we could accept that we didn't always need new, perfect, shiny medicines and electronics, it would put them in a sane price range.

Companies are not throwing away $$$ (0)

Anonymous Coward | more than 9 years ago | (#11988044)

Most chips that you buy have defects in them, especially memory. For years now chip manufacturers have been building redundancy into very regular structures like memories such that if a whole column is bad they use a spare one built for that purpose on the chip.

Chip companies are not throwing away money, most chips off the fab are inspected by high-precision cameras, then sumarrilly electrically tested before being bonded to a package (save money on not packaging ones that don't pass this test) Then tested and burned in according to a test that will exercise as much of the chip as possible.

Then there's the whole binning process where if the chip runs too hot you sell it as a lower freq chip, if the floating point unit doesn work sell it as one without it (remember 486DX), these days if one of the processors on a multi-cpu chip doesn't work, well it's now a uniprocessor.

Ask Intel (1)

freidog (706941) | more than 9 years ago | (#11988051)

how well that work with the P54 Floating Point rounding error.

People may not notice the problem, but if they ever find out it's there, they'll want it fixed, better to throw out a chip in the fab, than replace the product in the market.

You would have to know exactly HOW they fail (1)

droopycom (470921) | more than 9 years ago | (#11988120)

This theory seem simplistic to me.

It seems that what he proposes is to write new specs for each bogus chip.

1. You would design chip C1.
2. Then you build chips, supposedly as per C1 spec.
3. Then you check your chips against C1 spec
4. if not the same, then you write spec C2 according to what the buggy chip does
5. Now you can sell working C2 chips

In theory that works, except that it would be impossible to write a spec from the manufacturing tests results.

It might work for simple chips, such as Memory chips but anything like a graphic chip is going to be too complex to handle.

Each chip might fail in a different way, so you would have to classify the chips according to how they fail, you might get hundreds of them. If you get chips failing all the same way then its true you might find a use for them, but if they all fail the same way, then It means there is a problem in the fabrication process and I would rather fix the process.

Writing those manufacturing scan tests is not easy, they have to run quickly, be very compact...
Each test you add cost more money to run, it might not save you money in the end

I would love a defective chip in my system... (1)

FrankieBoy (452356) | more than 9 years ago | (#11988133)

..to match my defective Windows operating system. Is it me or is the quality of EVERYTHING going to hell. Pretty soon we'll be living in carboard houses and driving aluminum foil cars.
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