[Mesa-dev] R600 tiling halves the frame rate
j.glisse at gmail.com
Tue Oct 30 11:45:52 PDT 2012
On Tue, Oct 30, 2012 at 10:43 AM, Tzvetan Mikov <tmikov at jupiter.com> wrote:
> On 10/30/2012 07:12 AM, Patrick Baggett wrote:
>> Is your screen refresh rate 70 Hz? Because if so, that means that it's
>> syncing to the vblank on Mesa, and not doing so on the proprietary one.
> Unfortunately no. In fact the Gallium EGL/R600 doesn't support flip on
> vsync at all - eglSwapInterval is always 0. The output is a standard
> 60Hz LCD, plus I do get different, (but still low in absolute terms)
> frame rates with different chips. Off the top of my head:
> - HD5430 - 120 FPS
> - HD6450 - 140 FPS
> - HD6460 - 70 FPS
> - HD6750 - 400 FPS
> - HD6760 - 240 FPS
> I do think there is something fishy with the page flip though, which I
> am planning to investigate today. It is way too slow - a render loop
> which does nothing but a eglSwapBuffers() (no actual rendering
> whatsoever) runs at only 350 FPS. It should be either 60FPS, or thousands.
So tested, it's something inside egl that lead to this, same program
as yours with glut on X11 with 2d tiling enabled and 2d color tiling
have a slight advantage 140fps vs 137fps (windowed so there is a blit
which would account for a hugue chunk of perf diff with fglrx).
However using egl i got 70fps with color tiling and 74fps without. So
something in egl is slowing things down.
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