[Xorg-driver-geode] Driver Perf LX800

[Mart Raudsepp]

Hello,

On E, 2010-07-26 at 14:31 +0200, Christophe Lindheimer wrote:
> Hi.
>  
> My prob is just that I had much better perfomances with my old
> system...
> 
Yes, and what are your typical use cases. What programs and operations
are slow. Just the desktop environment in general, I assume.
> 
> I run a x11perf -rgbftext.
>  Old config :81300 / s
>  New config : 36000 / s

Are you sure -rgbftext measures what is important?
I guess it measures no anti-aliasing text drawing, not sure how we fare
there with the optimized code (that isn't in 2.11.8 or even GIT yet).
Is your desktop really configured to no anti-aliasing at all? We
typically benchmark the common case with x11perf -aa10text and x11perf
-aa24text for anti-aliased text

In the future it will be important for speed to not use subpixel
smoothing (the anti-aliasing style, that takes advandance of the fact
that LCD screens are made of red, green and blue subpixels), as that we
won't be able to accelerate anytime soon (if ever).
 
> But I guess (and hope) that Mart's analysis is OK and that the
> performances will get much better once the driver will be fully
> optimized...

Meanwhile you can force most things to software with the option

Option "MigrationHeuristic" "greedy"

in your xorg.conf or xorg.conf.d/ (with xserver-1.8+ if migrated to that
use already).

That should give a bit better results until you are able to have more
optimized driver.


There are patches on the mailing list for making text go 5-10 times
faster though. After those patches are finalized, we'll of course have
work ahead on optimizing various other rendering of the desktop besides
text drawing.


Regards,
Mart Raudsepp