Re: Athlon X2 can't see all 4G of memory, help please

From: Steve Wolfe (
Date: 07/28/05

Date: Thu, 28 Jul 2005 13:41:24 -0600

> The BIOS has a switch called S/W memory hole remapping, when OFF the BIOS
> sees 3.5G of RAM as does Linux. When ON the BIOS sees all 4G of RAM but
> Linux sees only 3G. I've given a mem=4096M to GRUB,

  If I recall, a certain amount of memory is reserved for use by PCI and
other devices, so you don't see exactly 4 gigs. In my opteron-based systems
with 8 gigs installed, /proc/meminfo reports between 7.3 and 7.7 gigs,
depending on the hardware in the machine.