4 Gig in new Prec 490 showing as 3 Gig?

[jarod at wilsonet.com (Jarod Wilson)]

On Thursday 03 May 2007 15:48:52 Derek Atkins wrote:
> Jarod Wilson <jarod at wilsonet.com> writes:
> > iff your kernel is built with PAE support, which in my world, is not the
> > case for the base kernel. Red Hat's stock i686 kernel is non-PAE, as
> > there are i686 systems that don't support PAE, and will fail to boot. Red
> > Hat also ships an i686 kernel-PAE package for those that need PAE. But so
> > far as I know, PAE is really only relevant/needed if you have *more* than
> > 4GB of RAM on a 32-bit system. That seems to fall in line with the rest
> > of Alex's comments below.
>
> Yeah, I suppose I could go install the PAE kernel to try it..
> I know I have 4GB.  But lots of places seem to imply that
> the chipset max is 3GB.
>
> I was hoping that Linux would be able to access it all, but
> I can't see how to get Linux to see that extra 1GB.

Yeah, some hardware simply isn't built to handle that much memory in an 
efficient manner. I have two different x86_64[1] systems with 4x 1GB stick 
in 'em, both running x86_64 Fedora 7. One can only access right around 3GB no 
matter what, the other can get at the full 4GB.

Note that the 3GB system is a desktop-class AMD64 board with 4 memory slots, 
the 4GB system is a server-class dual socket opteron board with 8 memory 
slots.

[1] so PAE vs. non-PAE doesn't even come into play

-- 
Jarod Wilson
jarod at wilsonet.com

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