Abysmal compositing performance with VSync enabled

[RealNC]

I had to watch two videos at once with mplayer (to visually compare them). Doing that revealed that fglrx is *slower* than molasses when having two opengl apps run at the same time with VSync enabled in a compositing environment (KDE 4).

So I tried running several instances of glxgears at once. Even with just two, the lag becomes intolerable. Add a third, and you feel like running Windows Vista on a 486.

Disabling VSync makes everything super-fluid again.

Is this normal and will we have to live with it? It sucks.

[kernelOfTruth]

I had 13 glxgears windows running with compositing (compiz-fusion) and no lags with VSYNC (in compiz) enabled!

tweak your cpu-scheduler / CFS and probably switch to compiz ?

[storma]

I just tested this as well and get the fps drop with only two glxgears running if Vsync is set in amdcccle. In compiz settings everything is fine.

[RealNC]

I had 13 glxgears windows running with compositing (compiz-fusion) and no lags with VSYNC (in compiz) enabled!

Not in Compiz. That doesn't work with fglrx anyway. You have to enable it in CCC (amdcccle).

[kernelOfTruth]

Not in Compiz. That doesn't work with fglrx anyway. You have to enable it in CCC (amdcccle).

found it & confirmed !

can this be fixed with the official Catalyst 9.10 ?

Many thanks in advance