945GM<->965GM huge performance differences when running GLXapps in parallel

[He, Shuang]

Eric Anholt wrote:
> On Tue, 2008-01-29 at 15:09 +0100, Jens Stroebel wrote:
>> 		Hi.
>> 
>> When I start the example-prog teapot on intel 965GM, it runs with 160
>> FPS BUT drops to astonishing 5 FPS when a glxgears is started.
>> 
>> On intel 945GM, this is along the lines of 60 PFS <-> 30 FPS (which
>> is 50%, compared to .. below 5% in the above case).
>> 
>> Can anybody tell me why this is so?
> 
> Not using TTM, I'm guessing?  Non-TTM context switching was much more
> expensive on 965.

I have tried these on my GM965, there's no such astonishing drop when
TTM is on.
and when INTEL_NO_TTM is set, it does have drop from 70FPS to 20FPS, and
the rendering is incorrect .

Thanks
    --Shuang