[LAU] question about RAM amount

[Mark Knecht]

On Fri, Aug 1, 2008 at 8:12 AM, Dave Phillips <dlphillips at woh.rr.com> wrote:
> Greetings,
>
> Yet another round of upgrades here. I installed another gig of RAM in
> each machine. The JAD box (32-bit) reads correctly at 3.1 G during the
> boot, but the 64 Studio box reads only 3.67 G. It's supposed to be 4
> gigs, what happened to the rest of it ?
>
> Mobos are identical Gigabyte boards, CPUs are both AMD64, so the amount
> should be supported, yes ? Video boards are also identical, with 512 MB
> on-board memory.
>
> The BIOS and dmesg yield the same report. Did I miss something ? DIMMs
> not arranged properly, or ... ?
>
> Best,
>
> dp

Dave,
   I'e not had to do this myself as I've never had 4GB but have you
enabled all the high memory, large memory options in the kernel? I
believe the kernel is limited to 4GB memory ADDRESS SPACE without them
and some of the ADDRESS SPACE is dedicated to other things in the
system, like mapping PCI bridges, peripherals and such. However when
you enable the larger memory models then I think that gets moved out
of the way and you see more of your RAM.

   Completely a guess because as I say I've never even used a machine with 4GB.

Hope this helps,
Mark