[Bioclusters] Opterons and Linux

Jeremy Mann bioclusters@bioinformatics.org
Mon, 19 Jul 2004 09:39:59 -0500 (CDT)

Farul M. Ghazali said:

> If your user-space app is compiled as a 64-bit binary, it will see >4GB of
> RAM (or whatever your RAM + swap is). If your app is a 32-bit binary, it
> will see al the 4GB of RAM it can actually address, but nothing more.
> However, the 32-bit binaries don't have to share the 4GB address space wih
> other processes unlike what you're seeing with a 32-bit kernel/machine
> now. Note that this is assuming you're running a 64-bit kernel of course.
> Cmpiling 64-bit apps was a bit confusing at first (mixing 32-bit and
> 64-bit libs during linking, etc.) but we got the hang of it after a while.

What OS are you using? I have SuSE 9.1 64bit on a dual Opteron with 4 gigs
of RAM. BIOS *sees* all 4 gigs, but SuSE with the 2.6.4 64bit kernel only
sees 3.19 gigs.

Jeremy Mann

University of Texas Health Science Center
Bioinformatics Core Facility
Phone: (210) 567-2672