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ramtest86 hangs but it’s not the RAM’s fault!

I was using the ramtest86 from a Ubuntu Intrepid startup disk (32 and 64 bit CDs). It was a machine with RAM problems (IBM eServer x346), so I wasn’t too surprised that ramtest86 hung during testing. Still, kinda annoying.
I had another similar machine (I have them here for some MySQL related testing) that was known to be probably good (no things are certain 😉 and interestingly it hung there also.

Using ramtest is just my “default” way of finding bad RAM, as it works on any box. But these IBM systems have a diagnostics mode which is essentially a flashrom-based PC-DOS with some basic drivers and a test tool. Cool!
So I tried that, and it worked fine on the “good” box. And found problems in a specific DIMM on the “bad” box.
Excellent. Progress!

Oh and it’s not realy that “cool” really since these boxes currently reside in my office, and apart form the noise from the hotswappable fans and disks, they are very good at heat generation. Let me remind you that it’s currently summer in Australia, Brisbane is in the subtropics anyway, and my office does not have aircon. If it were winter, it could perhaps act as a decent heater! 😉

Back to the story… it’s now going through the other ram banks in the “bad” box, and then I can rip out the faulty ones. Nice. But the question is, why does ramtest86 hang? These are dual Xeon 3 GHz boxes, in case you’re not familiar with the x346. Anyone else familiar with this tool just hanging on certain boxes, or perhaps architectures?

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