Ron said:
I tried reinstalling the second stick. It froze within 30 minutes. I removed
it everything is fine again. It apparently does have to do with that extra
stick (and consequently running in dual channel mode).
I wonder how thorough memtest86+ acutally is (does it also test dma (as
opposed to just poking and peeking different values in and from memory).
I don't know about Memtest86+, only Memtest86 and its cousin, Memtest
+, but they're supposedly very good and, among PC-based diagnostics,
second only to a very few others, including those from RST, used by
many 2nd and 3rd tier module manufacturers.
Good point about DMA. I don't know of any PC-based diagnostics that
use it. I also haven't seen any tailored for each chip's internal
layout, which can allow for more thorough testing without wasting time
on relatively useless generic test patterns.
Extra modules mean extra capacitance on the memory bus, which slows
signals and hurts timings, and BIOSes usually slow the timings to
compensate, not always enough.