Some benchmarks with Radeon and Xorg7.1
rscheidegger_lists at hispeed.ch
Fri Jun 9 09:01:47 PDT 2006
Paulo J. Matos wrote:
> I've tested X against three options: AGPFastWrite, EnablePageFlip and
> AccelMethod. Both of these have 2 possible values, True/False for
> the first two and XAA/EXA for the last one. I start fluxbox, 54
> processes are running with an average of 0% CPU, 138112 used RAM and
> 377896 free RAM. The benchmarks table is as follows (CPU is average
> during glxgears runtime and FPS are given by glxgears):
> Method EnablePageFlip AGPFastWrite FPS CPU
> XAA False False 702 10%
> XAA False True 702 10%
> XAA True False 978 14%
> XAA True True 978 14%
> EXA False False 661 10%
> EXA False True 661 10%
> EXA True False 661 10%
> EXA True True 661 10%
glxgears isn't really a benchmark.
That glxgears is slightly slower with exa is interesting though, I'm a bit
puzzled why the 2d accel method would make a difference, maybe there is
some additional overhead somewhere (dri client is more often interrupted
Pageflip won't work with exa so naturally you don't get any difference
> I should add that in all EXA configurations, the screen sometimes
> would generated distorted images on the top, disallowing a
> confortable use even if it happened to be better, which is not. So,
> currently I'm using XAA with only EnablePageFlip enabled.
> In fact, it is understandable that AGPFastWrite changes nothing since
> by closely analysing lspci I notice that my motherboard as FW+ and
> video card as not, so video card doesn't support FastWrite which is
Even if it works, it simply won't do anything for performance. You're
fortunate if it doesn't just lockup (happens on a lot of card/chipset
It should be noted that glxgears gains a lot more performance by
pageflip than normal apps (due to the very high framerate).
For another (big) boost you could enable hyperz (driconf or
hyperz=true), though again glxgears will benefit more than real apps.
> Hopefully, EXA gets better in later releases and performes better
> than XAA and without the distortion.
Well, there really shouldn't be a difference with 3d performance if exa
or xaa is used. If something like, say, quake3, would show exa performing
slower by 5% I'd be worried.
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