So, after finding a CD that had memcheck on it, I ran a memory test on the new system I had assembled but couldn't get working. Unsurprisingly, it produced a bunch of errors, especially in test 8. I tested the memory modules one at a time, and confirmed that one of them reliably failed test 8 with, while the other survived multiple passes of memcheck's whole arsenal of tests without skipping a beat.
OK, no biggie; I got a bad RAM chip, I'll return it. So we take it back to Fry's, I explain that I ran a memory checker on one of the chips and it came up bad (I even helpfully gave them a note indicating which of the two seemed to be the problem), and asked to exchange it for a new chip. The customer service guy vanishes, then comes back a while later with a different chip in a box. As we're preparing to leave, Kate notices that the "new" box is opened. "Why's that?" she asks. "Oh, testing," the customer service guy says.
Testing. That's good, right? So we shop a little, take the chips back, and I plug them in. I figure, hey, never hurts to be too careful, and boot up memcheck. BAM! Within half a second the screen turns red with errors. In comparison, with the first set of chips I had to run the tester for up to fifteen minutes before I got a test failure. Trying the chips individually, I discover that 300MB on one is just (as far as I could tell) gone. It fails every single test. The other one survives the first few checks, but fails test 8 just like the other bad chip I had. [
UPDATE: it's actually not that bad; it does seem to have problems, but it doesn't fail on every single run of test 8, and it was able to run the Kororaa live CD]
Now, as I see it, we have the following possibilities:
(a) My luck sucks and I just got three bad chips in a row.
Possible, but I've bought at least a half dozen memory chips in the past (not counting ones that came in preassembled systems) and I'm pretty sure this is the first, maybe second time I've seen a bad one. Three in a row? That's ridiculous.
(b) I screwed up and blew out the chips while installing them.
Unlikely for the same reason as (a). I may be shaky on some hardware stuff, but I know how to install DIMM chips. Killing one might be in the realm of possibility; killing three out of four? Don't think so.
(c) The chips aren't compatible with my motherboard.
The chips are listed as being DDR400, which ought to be perfectly compatible with the motherboard. They are installed in the proper configuration (according to the motherboard's manual); besides, one memory chip worked just fine.
Assume that (b) and (c) are indeed false: the chips are really bad and I didn't destroy them. This, combined with the fact that Fry's "testing" didn't catch the blatantly obvious problems with one of the new chips, make me wonder if
(d) Fry's decided to save costs by handing me a pair (maybe even two pairs) of chips that another customer had returned, on the theory that returns are on average spurious.
The main problem with this theory is that I don't see why they wouldn't have resealed the package; maybe they just suck at testing memory or didn't bother to. On the other hand, I have seen a number of complaints online about Fry's and other big retailers engaging in this practice. (e.g., Google for "Fry's restock")
Either way, whether it's deceptive practices or just plain incompetence, I'm afraid this hasn't left a particularly good taste in my mouth about Fry's, and I'll probably just try to get a refund and buy the memory elsewhere. The only downside is that "elsewhere" more or less means "online", which means no instant gratification. However, since "instant gratification" in this case has been more like "instant non-gratification", I'm willing to live with that.