We have a server at a clients that has been showing random signs of instability (random reboots and a couple of panics)
Suspecting hardware problems I brought it down and ran memtest86 on it.
Then something odd happened.
Memtest shows plenty of memory errors, spreading over pretty much the whole of the installed 512MB. When I stopped the tests halfway through the first pass there were two pages, the lowest error was at about 50MB the highest was at circa 430
But the really strange thing is that the error bits are 00000000 i.e the test data and "bad" data match perfectly. There is no ECC on this machine so how can the data I put in the memory and the data I take out be the same yet there be a memory error. Memtest clearly shows the "good" and "bad" column with matching data but still flags these as errors.
I have ordered replacement RAM anyway, but I was just interested in what other type of memory error I am seeing here ?