Misreported VRAM

[Alex Deucher]

On Tue, Dec 8, 2009 at 6:07 PM, Ancoron Luciferis <ancoron at chaoslayer.de> wrote:
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> Jerome Glisse wrote:
>> On Mon, Dec 07, 2009 at 06:54:13PM +0000, Mike Lothian wrote:
>>> I have a Radeon 4650 (RV730) :
>>>
>>>  01:00.0 VGA compatible controller [0300]: ATI Technologies Inc RV730
>>> PRO [Radeon HD 4650] [1002:9498]
>>>
>>> This should have 1GB DDR2 VRAM on board however my dmesg states differently
>>
>> So far we don't use VRAM beyond PCI aperture which is 256M on your
>> system. I am planing on adding support for unvisible ram this week.
>>
>> Note that i don't think we have a driver which can take advantage
>> of such amount of VRAM yet, except if you are driving 2 30" screen.
> ^^
> And that is exactly what I'm planning for my X1950XTX (the first one
> with 2x Dual-Link-DVI).
>
> And with the newer HD5000 series AMD is going for triple ones, just like
> Matrox did already years ago.
>
> As another question in this area, I always see this message on startup
> in my Xorg.0.log:
>
> (II) RADEON(0): Cannot get VRAM scratch space. Allocating in main memory
> instead
>
> As it is an INFO I assume this is not critical and all things work but I
> always asked myself if this may cause any performance loss?

This is only used for some tables for atom-based modesetting.  It in
no way affects performance.

Alex