Re: 4GB RAM

[Dan Shearer <dan@shearer.org>]

On Tue, Feb 10, 2004 at 03:59:09AM -0600, Chris Cheney wrote:
> On Tue, Feb 10, 2004 at 09:16:25AM +0100, Andreas Wohlfeld wrote:
> > On Tue, Feb 10, 2004 at 09:03:30AM +0100, Lionel Elie Mamane wrote:
> > > NForce3 150 Pro chipset) with 4GB of memory installed: The BIOS (and
> > > thus Linux) recognises only between about 2.5GB and 3.5GB of RAM,
> > > 
> > > Does anyone have any sort of clue what is happening here?
> > > 
> > You have to read the mainboard manual. It states that this is normal
> > behavior due to memory space allocation of chips on the mainboard and
> > graphics card.
> > 4 GB minus 0.4 GB for mainboard chipset minus AGP apterture size sounds
> > about right.
> > 
> > It's a limitation of the 32 bit architecture. It does not happen with
> > server mainboards in 40 bit flat or 36 bit PSE mode.
> 
> Is there a way to go into that mode with any board, eg 64bit native
> Debian? Or does it require bios support?

LinuxBIOS.
http://www.clustermatic.org/pipermail/linuxbios/2003-November/005995.html
Choose your PCI hole size, recomile, reflash. It is as easy as that to
say for someone who doesn't yet own an Opteron board :-)

-- 
Dan Shearer
dan@shearer.org