[CentOS] segfaults with 8 gig of ram

[John R Pierce]

Morten Torstensen wrote:
> tblader wrote:
>> Thanks.  I ran memtest86 off a knoppix5.1 cd for about 12 hours
>> on all four sticks.  It made 6 passes and did not return any
>> errors.  Perhaps I should have left it run longer?
>
> I don't trust memtest86 for 64-bit mode kernels... I've seen examples 
> of it running just fine for days, when the kernel barfs after an hours 
> usage. It is just 2 machines, so not a large sample from my side.
>
> Clocking down the memory helped in one case.
>

I do think a 64bit version of memtest86 would be a good thing...   I'm 
unclear how a 32bit app could test memory above about 3GB unless its 
playing the PAE game (3GB because in a 32bit system, the PCI bus 
peripherals take about the top ~ 1GB for their I/O space, so the ram has 
to be mapped to a higher physical address, only accessible via PAE...