[CentOS] Re: segfaults with 8 gig of ram

I seem to recall there were some generations of Opterons where if you 
ran 3 or fewer banks (6 or fewer dimms, balanced for dual channel), you 
could run at PC3200 speed, but if you populated all 4 banks (8 dimms), 
you had to downgrade the memory bus to PC2700 or something.     Could be 
you're running into something like this.