very slow performance of glxgears (68 fps)
johnflux at gmail.com
Sun Feb 1 20:49:54 PST 2009
2009/2/1 Ian Romanick <idr at freedesktop.org>:
> On Sat, 2009-01-31 at 02:30 +0000, John Tapsell wrote:
>> 2009/1/31 Bryce Harrington <bryce at canonical.com>:
>> > On Fri, Jan 30, 2009 at 01:29:49PM -0800, Eric Anholt wrote:
>> >> > $ glxgears
>> >> > Failed to initialize TTM buffer manager. Falling back to classic.
>> >> > 300 frames in 5.0 seconds = 59.884 FPS
>> >> > 299 frames in 5.0 seconds = 59.621 FPS
>> >> > 300 frames in 5.0 seconds = 59.818 FPS
>> >> glxgears is not a benchmark.
>> >> We sync to vblank because running glxgears at 1000fps is dumb.
>> > I am going to go out on a limb and guess we're going to see a crapload
>> > of reports of "performance regression" due to reduced glxgears frame
>> > rates.
>> What was the purpose in this change? I have never heard a user
>> complain that glxgears is running too fast, and that they want it to
>> vsync. What's the use case of this change exactly?
> It has nothing to do with gears running to fast. It has to do with
> running real apps at crazy framerates and sucking power (and battery).
> It is also used to avoid tearing, though I don't think we've got that
> quite right yet.
Out of interest, which apps specifically have too high frame rates?
And why can't those apps vsync if that's what they intend?
There are cases were apps want to run as fast as possible - for
benchmarking etc. Are these apps now broken by this change?
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