Re: problem : quantity of memory available

[Max <relf@unn.ac.ru>]

I've faced exactly the same problem with my new Tiger K8W motherboard and 4G of physical memory.
Originally Linux reported only about 3G of total memory available (the exact amount seemed to depend on "AGP apperture size" setting in the BIOS setup).
With a new BIOS version 3.0 I was able to remap PCI area out of first 4G address space and got full 4G of memory available to the system.
The setting in the BIOS setup is called "SoftWare Memory Hole" which sounds quite obscure but it works just great!

Max

Paul Brook wrote:
> On Thursday 28 October 2004 13:19, Fuhr Guillaume wrote:
>
> > Hi !
> >
> > I run debian on a dual opteron system with kernel (
> > kernel 2.6.7-5-amd64-k8-smp ) and 2GB of memory.
> >
> > I have add 4GB of memory on this computer and when i verify quantity of
> > memory available (with "dmesg | grep Memory" for example), the result is  :
> > Memory: 5081952k/6291456k available (1684k kernel code, 0k reserved, 987k
> > data, 152k init)
> >
> > So i want to know why there is 1 GB that i can't use :(
>
>
> This could be because of the PCI address space, although I thought this was 
> only usually 0.5Gb.
> This is usually located at the to of the 4G physical address space.
> Some bios allow you to remap this section of physical memory above 4G so that 
> all physical ram can be accessed. This is often disabled by default to 
> provide the maximum amount of physical memory to legagy 32-bit operating 
> systems.
>
> Paul