Radeon Xpress 200G Memory size

[Alex Deucher]

On 1/20/06, Erwin Rol <mailinglists at erwinrol.com> wrote:
> On Fri, 2006-01-20 at 12:09 -0500, Alex Deucher wrote:
> > On 1/20/06, Erwin Rol <mailinglists at erwinrol.com> wrote:
> > > Hey all,
> > >
> > > I have a question, what are the relations between the different ways of
> > > checking how much memory is used for the integrated graphics chip in the
> > > Radeon Xpress 200 ? I tired lspci (the size of the largest PCI region,
> > > xorg.logs (the size int10 reports as is found in the Xorg.log file),
> > > grub (the memory grub reports at the boot screen) and windows XP64 (the
> > > size the XP device manager reports) to check how much memory is used.
> > > When i select 16M, 32M, 64M or 128M in the BIOS for the UMA size i get
> > > the following values.
> > >
> > > BIOS    lspci   xorg    xp64    grub
> > > 16M     64M     3072k   16M     632k/2078656k
> > > 32M     64M     7168k   128M    632k/2062272k
> > > 64M     128M    15360k  128M    632k/2029504k
> > > 128M    256M    31744k  256M    632k/1963968k
> > >
> > > These values just look weird to me, is there a explanation on why they
> > > look like that ?
> >
> > Xpress chips need to be treated like IGP chips (the info->isIGP flag
> > must be set in the driver) so ram detect is currently wrong in the
> > xorg driver (this should be fixed by daniels latest commit in xorg
> > cvs).
>
> That would than explain the memory size xorg finds, but the lspci output
> still looks weird, why does it need a region that is bigger than what is
> setup in the BIOS, and why is it so "random". Shouldn't the BIOS setup
> the PCI ranges, if so , why are they different on lspci and XP ? This
> all just looks really weird to me.

the sizes in lspci are the sizes of the aperture, not the amount of
vram. They do not always correspond, even for cards with discrete
vram.

Alex

>
> - Erwin
>