Are Bad RAM Chips Common? 78
A semi-Anonymous Coward asks: "I recently built myself a new system using a mainboard which required using registered DDR SDRAM -- the motherboard will not work with unbuffered / unregistered memory, and I wanted the extra integrity provided by registered memory anyway. To my amazement, both the memory I purchased with the board and one of two other sticks I purchased were either defective or simply incapable of working with the board (which is the Chaintech 7KDD, BTW). About how often do people run into defective memory, and do they see them from the 'reputable' manufacturers as often as they do the 'no-name' ones? Now that I've spent a ridiculous amount of money on this, I'm a lot more wary."
When lives are at stake ... (Score:4, Informative)
When iquanas are at stake ... (Score:1, Offtopic)
Re:When lives are at stake ... (Score:1)
Re:When lives are at stake ... (Score:1)
Daniel
Re:When lives are at stake ... (Score:4, Informative)
The local hardware shops will eagerly replace my cheapo RAM with different cheapo RAM but they can't replace 10 hours worth of diagnostics, lost files, scrambled data, the half hour each way drive it takes to get to their store, etc...
What happens if the RAM is marginal only at certain temperatures or under certain loads, circumstances they can't replicate on their test gear? You go back to the house and pop it back in and go back to having problems, but this time you are SURE it isn't the RAM so you start replacing other parts (mobo, video card, NIC, caching SCSI RAID controller card) all out of your pocket trying to make it stop blue screening (or whatever) and be a stable work environment
Once you start using the hardware for work the cost (value) of the hardware is negligible compared to the cost (value) of the actual data
Re:When lives are at stake ... (Score:2)
Daniel
Re:When lives are at stake ... (Score:2)
Crucial is boring...and I like it (Score:2, Informative)
Crucial, Corsair, etc. (Score:2)
Crucial aren't perfect -- we've had the odd dodgy thing from them at work -- but their service is excellent and their quality is generally high, so I'd recommend them without hesitation. They're well worth the small price premium over no-name brands without the same quality, compatibility guarantee, etc, IMHO.
There are other makes, Corsair for example, which are claimed to have even higher specs. You do pay a lot for that tiny bit extra, though. Unless you're heavily into overclocking (in which case I'm s
Re:When lives are at stake ... (Score:1)
lifetime warranty and dirt cheap prices
One out of dozens, perhaps hundreds (Score:2)
occasionally (Score:4, Informative)
Re:occasionally (Score:1)
At least, Windows is not that much bug-ridden anymor
Never... (Score:2)
Cheap ram = bad ram (Score:5, Informative)
1.) We get cheap stuff and save you money. I make it very clear that it may not work
2.) We get Normally priced ram and be sure its good
Of the few people that did not want to spend the money to get a good brand even with me warning that its a bad idea about 1 in 3 ram chips did NOT work. I've NEVER had a good brand (crucial, kingston etc) fail even 1 time. I dont' gamble on my system I use Corsair XMS and thats what i recommend but anways thats what i've found.
My Rough Stats:
Cheap Memory 30%+ failed Good Memory 0% failed this is only dealing with about 100 experiances in the last few years, i don't do much side work.
Re:Cheap ram = bad ram (Score:1)
I've also had 100% success with Crucial and good name RAM. One caveat I have to mention, we had serious trouble using Kingston RAM on a Tyan TigerMP. Memtest86 didn't turn up anything wrong, but the OS would hang within an hour of uptime. Never did quite figure that on
Re:Cheap ram = bad ram (Score:2)
Re:Cheap ram = bad ram (Score:1)
We have one that we can only run in single processor mode fo
Depends the lot and where you get it (Score:2)
When in doubt, test.
Bad Memmory... (Score:2)
As a side thought, with ever increasing RAM densities/capacities the chance for error and bad modules up. It's just a fact of the manufacturing process. Make sure not to forget about that.
It's all with the static. (Score:1)
Avoid risk - use less memory. (Score:3, Interesting)
Re:tHrashing, not trashing (Score:1)
I returned a stick 12 times to Fry's once (Score:1)
My experiences (Score:3, Interesting)
My SGI Indy is using old 72-pin SIMMs that I found on my (carpeted, read: static-inducing) floor under my desk.
My SparcStation 20 uses RAM that was shipped to me rattling about in a cardboard box without any packaging material whatsoever.
My K6-2/400 used crappy no-name (not even a brand to be found on the chips themselves) 256mb PC100 DIMMS
My Athlon TBird-1.4 used the cheapest no-name crap DDR RAM I could find on Pricewatch - 512mb of it - but at least Infineon's name was printed on the chips.
My Athlon XP1800+ used just about the cheapest RAM possible (I bought it from NewEgg instead of some other vendor for about $2 more) with no names on the modules or chips.
A Dual Athlon MP2000+ server I built uses no-name Reg. DDR266 / 512mb from a Pricewatch low-baller.
My current P4/2.4 uses 256mb DDR266 by OCZ Systems, and not because of the brand recognition (who the hell are they?) - it was super-cheap. I bet if I removed the RAMsink on it, the chips would be nameless.
None of these systems have ever had memory problems. They rarely, if ever, crash (or at least they didn't crash when I had them - some have passed on into the hands of friends). Maybe I'm just one really lucky bastard when it comes to RAM, but I've never had any problems buying the cheapest shit memory so that I could save a few bucks.
Also, somehow, I have managed never to kill a component with static electricity. The worst that's happened is that I rebooted my Atari 800 by zapping it right on the motherboard while it was running. In fact, the only component that I've ever bought or installed that didn't work was a Sun Creator3d framebuffer - the only component I've ever used an anti-static wristband to install (because there was a free one in the box) and it was DOA with big vertical lines running through the picture at regular intervals (4 pixels). Well, that and two Fibre Channel drives that exploded, but that's because I was hot-swapping them and shoved the power connector into the (worn-down, self-installed) receptacle backwards.
Re:My experiences (Score:5, Insightful)
You've been lucky on RAM for sure. Now about this static discharge thing. I also never used to use wriststraps or any other static precaution working on home stuff. I always did it right at work because it was required, but at home I routinely did just about anything I could to static damage them because I knew it was unlikely to cause a problem. My experience was always that the components worked fine anyways, and that ESD damage must be such a low occurence that you're just not likely to ever see it so it's not worth the trouble.
However, later on down the line I learned the error of my ways. I was failing to understand the nature of ESD damage. Someone finally clued me in. In short, ESD damage *does* happen with a surprisingly high frequency when you handle components unsafely, but you don't notice because the damage takes time to show. Essentially the high voltage of the ESD (ESD like when you shock yourself on a doorknob is very high voltage, it's just very low current) is destructive to the transistor junctions, but it usually doesn't cause immediate complete failure. A few days, months, or even years down the road, the junction will prematurely break down, having had a shortened lifespan because of the ESD damage.
So those components that failed on you after a few good years of service that you chalked up to just failing from age probably failed to a large degree from ESD back when you first installed them, and had you used the right precautions, they might've lasted a lot longer. Now that I understand this, I'm a lot more careful about ESD even at home. From what I read, the long-term effects of ESD over a large sample are better felt by electronics companies. They can actually see the warranty return rate on their chips drop consistently when they put better ESD precautions into place, although it may take a few years to see.
Re:My experiences (Score:4, Informative)
ESD damage *does* happen with a surprisingly high frequency when you handle components unsafely, but you don't notice because the damage takes time to show
I used to work at a semiconductor manufacturing facility once upon a time. Let me just say that this is 100% correct.
My employer spent a lot of money on ESD prevention because ESD errors were the worst kind of errors. Sometimes the chip would fail catastrophically, but usually it would pass probe and test and get shipped, only to fail prematurely in the field (latent failure). This is obviously much more expensive than finding the problem before the device ships.
Another common misconception is that you need to feel the ESD charge - like walking across a carpet in sock feet and touching a doorknob - in order for damage to occur. This is false - most electronic components can be damaged at a much smaller voltage than you can feel in your body.
My best advice is that simple ESD precautions like a wriststrap are cheap, so use them.
CMOS Electronics Primer - ESD Damage (Score:3, Informative)
Essentially the high voltage of the ESD (ESD like when you shock yourself on a doorknob is very high voltage, it's just very low current) is destructive to the transistor junctions, but it usually doesn't cause immediate complete failure. A few days, months, or even years down the road, the junction will prematurely break down, having had a shortened lifespan because of the ESD damage.
Indeed.
Memory chips - and most other components within any computer less than fifteen years old - use CMOS logic. CMOS st
Re:My experiences (Score:5, Informative)
Out of sight, out of mind.
Being a former test lead for a memory diagnostic tool, I'd bet you had plenty of memory errors. When they occured, they didn't 'look' like memory errors, so you treated a different problem. Your fix 'worked', so you claimed sucess and moved on. Other errors might not have symptoms -- even if corrupton did occur -- so you didn't notice anything was wrong.
The stats given by others -- ~30% failure on cheap memory and 0% on good within the first month -- are close to my experiences. IMNSHO, the intial numbers are the same (~30% & ~0%). Over the lifetime of a system +10% of both cheap and good memory tends to fail (or get wrecked by bad power).
To catch the +10% failure rate on non-ECC memory, and to catch memory subsystem errors in general, I run extensive tests on systems that can be taken down about once a year -- this is beyond any tests to diagnose flaky behavior.
Memtest86: It is excellent and as good as any other memory diagnostic software I've ever used when running all tests. As a matter of course, I add memtest86 to the boot menu on all x86 systems.
BIOS memory tests: The boot up memory tests are useful only to identify that the memory exists, so if possible I turn them off.
+3 interesting? (Score:2)
There's no reason to mod dumb luck up, only to tell FueledByRamen to go buy lottery tickets.
no bad expieriences at all... (Score:2)
I always hadle my computer parts with extreme (some say paranoid) care for 'static I must add.
Save one occasion when I mixed four different kinds of SDRAM in a AMD K6/2 based system. And I talk different timing and clock specs, different number of chip on each RAM bar. I got segfaults and bluescreen a
Run Memtest86... (Score:5, Informative)
As for no-name. Usually grade 'a' ram will run at a lower cas rating, where some of the generics might work at a higher (and slower) setting. Stuff that rates at PC-100 CAS 2 might only work at PC-133 CAS 3. (dang, showing my age) The good stuff tended to be able to run stable at the faster FSB and CAS settings. My time is worth more than the ~$30 bucks between solid and guesswork.
If your not pushing a system hard - cheap ram might just work. A few years back a local vendor had some dirt cheap no-name 128M sticks that ran as fast as my mushkin stuff. Go figure. You role the dice, but it matters less if you are not pushing your settings hard.
Re: (Score:2, Informative)
BIOS limitation (Score:2)
About your dual Pentium...it sounds like your BIOS. Until a few years ago, many BIOSs were not designed for all combinations of memory size. (When you say "larger sticks", I assume you mean larger memory capacity.) In those types of motherboards, your memory has to be placed in certain orders according to how much memory the stick contains. Some of them were so restrictive, they would only support the same sizes. If you had one 8MB stick, your only choice was to use another 8MB one. A 16MB+8MB combo wouldn'
Re:BIOS limitation (Score:2)
an example of such a board is the Intel SCB2 [intel.com].
[that board can go up to 6GB ram and has 6 sockets]
Bad engineering, bad commerce. (Score:5, Insightful)
When you put oil into your car, you know that the oil companies and the car companies have gotten together with the American Petroleum Institute to set standards so that as long as your owner's manual says "API SG" and the oil you buy says "API SG" or better, that oil will work in your car. And you can use Mobil Oil to top up an engine filled with Quaker State without losing any sleep over whether their chemistry is compatible.
You don't rely on friends' stories of whether Quaker State is better than Shell Oil. You know that regardless of the price of the oil, if it says API SG it meets API SG specs and if your car says API SG specs are good enough, they're good enough.
It doesn't benefit anyone if your engine seizes up, and it doesn't benefit anyone if your computer crashes.
It's simple, it's easy, millions of consumers who aren't chemical engineers buy engine oil every day without wrecking their cars.
Why is it expecting too much for computer vendors to do the same?
And, while we're at it, why don't all computers use parity-checked memory? This was standard on 100% of all computers before the micro age, and for some reason people started putting in non-parity memory to save money and asserting that "it works."
And our computers crash a lot, and nobody knows why and nobody does anything about it and everyone just accepts that that's the way computers are...
Re:Bad engineering, bad commerce. (Score:1)
Re:Bad engineering, bad commerce. (Score:2)
I doubt your issues are with bad/incompatible RAM, or even hardware. With my experience, the vast majority of today's system/application crashes are due to highly buggy software. Mostly from one specific company.
My system doesn't crash a lot, and I have a crappy buggy VIA MB. Yeah, the thing would lock up under heavy disk load, but I found out it was a bug w
Re:Bad engineering, bad commerce. (Score:2)
as memory become better, most errors were detected at post and the extra bit really wasn't needed.
it not only makes the memory cheaper, but also the memory management stuff of the system board gets cheaper and simpler.
eric
No context, so take with grain of salt (Score:2)
If you keep buying a component that repeatedly fails, it's worth triple-checking to make sure that whatever you're plugging the component into is working. Have you taken known-good RAM and plugged it into the motherboard to make sure that works?
There is an art to learning when not to do this, because the component you are plugging into is actively frying the pluggable component, but in general thi
Summary (Score:3, Informative)
1) whenever you buy a new stick of RAM, run memtest 86 on it for an hour or so. It can save you weeks of problems.
2) Use a grounding strap. ESD damage is a serious problem, and especially in the winter months, can easily lead to zapped parts. In fact, use a strap whenever you open your box! I even have a roll-up ESD mat for serious surgery.
I have actually had memory go bad in my PC right when I was using the PC: it was good one minute, then bad the next. I have a nice APC UPS working as a surge protector. THe memory was some premium stuff too - Corsiar XMS memory. I hadn't touched the inside of the box for a few weeks (hard to believe, huh?), and I was practicing with the 203 on America's Army, and I suddenly got a win2k BSOD (which has a lot more words, but is basically just as useless as the win98 BSOD). So:
3) test your memory periodically - like every 6 months or so.
4) Maybe your motherboard has some debris in the memory slot or a sliver of metal shorting some pins out.
Re:memtest86 not a good test (Score:2)
Erm, there are actually a few programs out there called "memtest86." I promise you that if you're using this one [memtest86.com] then if that stick fails consistently (erratic RAM failure is pretty much unheard of outside of unusual operating environments) then memtest86 will find the problem.
Re:Summary (Score:2)
Details on what I've seen and recommend are here [slashdot.org].
1. An hour long test only catches the most basic errors. You sleep, right? Run all tests and use that time to check it out. I've run memtest86 for a day and a half at times...and only toward the end does an error get detected -- sometimes not caused by the RAM but the memory subsystem (toss the board).
2. See above.
3. Yep. I only do it 1x a year or when something looks wrong or just strange. The more often the better.
4. Yep. Along th
Re:Summary (Score:2)
Hee. An hour isn't much with memtest86 unless you're testing a 128mb 800mhz RIMM. :-)
Run it until ALL of the tests have completed at least once with the CPU cache disabled. Unfortunately, this does take quite a while. But give a day to it. At today's densities, RAM is pretty easy to damage, and it's nice to be sure.
Re:Summary (Score:2)
When I've had bad memory, the first iteration always flagged it. Of course, a more complete overnight run would be better. But, in my experience the first 30minutes finds 90% of all memory errors.
ESD strips are not required (Score:3, Interesting)
ESD advice for system self installers:
- Ground yourself to the metal chassis or something comparable on your system before you start assembling things. Do this frequently.
- Leave things in the anti-static bags until you're ready to put them together.
- Don't handle ram chips
Bad sockets? (Score:2)
Everyone + dog had problems with the ABit KG7 not letting Micron memory work, but working wonderfully well with cheap nobody-brand sticks. The suggested solution is usually "ebay your memory, remove the board and put it on a hard surface to install your sticks, or be prepared to flex the hell out of your board and pray nothing breaks."
Re:Bad sockets? (Score:3, Funny)
You're right about the flexing though - only if you've not installed the motherboard correctly. I did this once. There's a screw mount near the ram slots that I overlooked, and if it's not there the motherboard will flex right down to the case's motherboard mounting plane. This being my first experience with an ATX power supply (ie: ones that aren't actually off when the computer is shut down, and hav
Common sense... (Score:1)
Never happened to me (Score:2, Funny)
My one encounter with "bad" ram was in a computer hardware class I took a few years ago. Two other classmates and myself were usually given special tasks by the professor because the class was so stupidly easy for us. One day, after we finished our two hour lab in fifteen minutes he gave us a stack of 8meg simms (this was a while ago) to test with some software he had. We tested about six and ever
Motherboard? (Score:3, Insightful)
Re:Motherboard? (Score:1, Insightful)
Re:Motherboard? (Score:2)
With cheap RAM, very common (Score:2)
Expensive name brand stuff is usually perfect. No-name computer show memory often as all sorts of flaws that redundancy in the chip takes care of.
Chaintech (Score:2)
There's your problem right away. Shitty motherboard manufacturer. Buy if your going ECC Ram, at least get a respectable motherboard like Asus or Intel.
Intel has a list of tested and approved RAM on it's web site and it will guarantee that they work together.
The cheap motherboards and RAM are cheap because they have not gone through rigourous testing to make sure that they are ok. It's the same with brand vs no-brand stuff. Often the same manufactur makes the components, but because the bran
Bad experience here too. (Score:2)
The place was Sonnam Computers Toronto, College and Spadina, one of the lowest cost places Ive known in Toronto... So I got the chips, plug in and it works fine.. I install Windows 98, utilities, antivirus etc, works perfect.. now as I am playing Unr
Re:Bad experience here too. (Score:2)
Re:Bad experience here too. (Score:2)
I have quite a few of those boards. Haven't had one single problem with them.
Bad Chips? (Score:1)
Is it possible for only one chip to fail? Of course, this was probably the cheapest possible RAM I could buy.
Re:Bad Chips? (Score:1)
Re:Bad Chips? (Score:1)
Bad RAM (Score:2)
Now, all of the easy diagnosis (bad memory cell, row or column) were handled by QA. The really bizarre failures came to me. Glitches that occured only after the chip was in standby for more than four seconds, errors that only occured if the addresses were accessed in a certain order, not to mention marginal voltage and temperature performance...
There
Just went thru this, lost a year! (Score:1)
Second stick survived a couple of 4-6hr runs on memtest86 w/no problems. W98 installed, BSOD'd little more than usual, but I considered it secondary anyway. Mandrake install now would run, but kept dying m