in Ubuntu 9.04 RELEASE the same problem
hardware notebook IBM lenovo X61s, i965GM
when system is idle:
glxgears
3814 frames in 5.0 seconds = 762.697 FPS
3870 frames in 5.0 seconds = 773.926 FPS
and when i move any window on screen (terminal or open folder):
glxgears
442 frames in 5.0 seconds = 88.394 FPS
389 frames in 5.0 seconds = 77.557 FPS
371 frames in 5.0 seconds = 73.928 FPS
in Ubuntu 9.04 RELEASE the same problem
hardware notebook IBM lenovo X61s, i965GM
when system is idle:
glxgears
3814 frames in 5.0 seconds = 762.697 FPS
3870 frames in 5.0 seconds = 773.926 FPS
and when i move any window on screen (terminal or open folder):
glxgears
442 frames in 5.0 seconds = 88.394 FPS
389 frames in 5.0 seconds = 77.557 FPS
371 frames in 5.0 seconds = 73.928 FPS
and Xorg at this time %CPU > 56