Comment 33 for bug 252094

Without compiz:
jan@jan-x61:~$ glxgears
2798 frames in 5.0 seconds = 559.539 FPS
2671 frames in 5.0 seconds = 533.488 FPS
2760 frames in 5.0 seconds = 550.889 FPS

With compiz:
jan@jan-x61:~$ glxgears
2293 frames in 5.0 seconds = 458.450 FPS
2360 frames in 5.0 seconds = 469.041 FPS
2300 frames in 5.0 seconds = 459.050 FPS

So the framerates are about the same.