Slashdot Mirror
Firms Get Away with Selling Untested DRAM
peppytech75 writes "Melanie Hollands in IT Manager's Journal reports that 'In recent months, some Asian DRAM memory manufacturers have been getting away with selling untested ("UTT") DRAMs. Disturbingly, the practice seems to be getting traction at the lower portion of the module business. This is being done mostly by Taiwanese DRAM makers, who are undercutting the tier-1 guys by selling untested and unmarked parts.' What's the solution here? Or is there an actual solution to what amounts to pirate companies issuing counterfeit parts?" (IT Manager's Journal, like Slashdot, is part of OSTG.)
Here is the obligitory Memtest86 post. It's a great program, and chances are that you might already have a copy on your Linux install CD depending on the distro. There are even kernel patches that allow you to avoid the bad bits if they are isolated enough.
Solution:
Same here. I used to buy whatever was cheapest, but after the time that a series of flakey bugs was solved by switching to good quality DRAM, I'll never go back. I probably spent two days troubleshooting it, which at my hourly rate, is many times the amount I "saved" by buying cheap memory.
Blatant promotion: I've never had a bad stick from Crucial
Chip H.
If you RTFA, the author was saying that these unmarked and untested DRAM chips can later be marked as if they came from a Tier 1 manufacturer. These chips can then be sold for a premium, yet still less than the Tier 1 price. In that case unmarked and untested = pirated.
I just buy ECC RAM.
/proc/ram or /proc/mc/0, see the statistics and instantly find if the memory is seeing errors or not. Here I do see a corrected error or two sometimes, although very infrequently. But it's indeed very nice to know it's been corrected.
Sure it's more expensive, but it's great. If the computer does something strange I know that I can check
However, even if it's ECC I still wouldn't like at all knowing that it's not been tested. ECC has limits to the corrections it can make, after all.
Whenever we buy new RAM, mostly as part of new PCs, we run Memtest86. It's easy to do, it takes a while so do it overnight. There's so much that can go wrong with RAM, even with "good" RAM: it might not work together with the board, the SPD-timings might be off, whatever. Every once in a while we find some RAM that doesn't work for us and return it to the shop. We never had any problems at all to get it exchanged.
For hardware-sellers it's probably more expensive if they have to factor in a certain return-rate (and the overhead for that) so they will look to it that the RAM they buy is ok. That way market forces will work for the benefits of all of us: untested RAM will, in the end, be more expensive than tested RAM. It's much easier and cheaper to do RAMtesting factoryside than having it returned by millions of customers.
Of course that doesn't work if you buy your PC in a supermarket, but even for cheap PCs it's better to configure them yourself than buying crap. That way you can specify exactly where to save money and if anything breaks you get it fixed much quicker.
"By the way if anyone here is in advertising or marketing... kill yourself." -- Bill Hicks
The motherboard supports generating an interrupt when something happens. You can tell it to do that in case of a corrected error, uncorrected error, or never. I think Windows will BSOD when that happens, so I'd just set it to do it on an uncorrectable error. Then it will crash, but at least it will stop things before they mess up something important.
/proc you can monitor with detailed statistics about how many errors were corrected. IIRC, without specific support Linux will generate an oops, but continue if the board generates an interrupt. The patches can be told what to do in that case.
On Linux you have the ecc-linux(2.4) and bluesmoke(2.6) kernel patches, which will give you a file in
I suppose there must be some software to get all the features on Windows too, but I don't know where to get it.
I was surprised at just how far companies like Kingston have to go to honor their lifetime warentee. I worked for SGI a couple of years ago and I was using a old beat up (8 years obsolete and it still performs decently!) Personal Iris 4D/35 when after a power failure it failed to boot complaining about bad memory. So I pull the thing apart and find that it has an enormous board with 16 SIMM-like slots. I pull out the offending module and notice 2 things:
1. It is obviously some sort of custom memory module unlike any I had ever seen before, and hasn't been manufactured in years and years.
2. It has a Kingston Memory sticker on the front.
So, I decide to see just how good the "lifetime warentee" is. Amazingly enough, they send me an RMA label right away and within days I have a brand new memory module and the system is back up and working perfectly! I was truely amazed that they were still willing to honor their agreement (I've had many bad "lifetime" warentees before where the "lifetime" is defined as 1 year or other BS) without complaint or hesitation.
I read the internet for the articles.
But Prime95 confirms that no bit anywhere in nearly the complete memory space ever spuriously changes. I have seen plenty of memory that passes metest86 that fails prime95.
Based on my experience, Corsair will replace memory that fails prime95. Mushkin will NOT (despite a "lifetime" warranty); they basically told me that memory can't be expected to be 100% perfect all the time and that prime95 was too strenuous; if it passes memtest86 there will be no replacement. My other modules (from Geil, Samsung, and a few old no-name sticks) have always been perfect. IMO it's unconscionable to sell untested ram given how hard it is to return.