Dell Latitude D600 vblank_mode=0 glxgears

vblank_mode=0 glxgears

ATTENTION: default value of option vblank_mode overridden by environment.
ATTENTION: default value of option vblank_mode overridden by environment.
ATTENTION: option value of option vblank_mode ignored.
1453 frames in 5.0 seconds = 290.570 FPS
1543 frames in 5.0 seconds = 308.556 FPS
1450 frames in 5.0 seconds = 289.825 FPS
1630 frames in 5.0 seconds = 325.871 FPS
1798 frames in 5.0 seconds = 359.265 FPS
2634 frames in 5.0 seconds = 526.671 FPS
3044 frames in 5.0 seconds = 608.747 FPS
3134 frames in 5.0 seconds = 626.761 FPS
2903 frames in 5.0 seconds = 580.424 FPS
2726 frames in 5.0 seconds = 545.121 FPS

glxgears
Running synchronized to the vertical refresh.  The framerate should be
approximately the same as the monitor refresh rate.
1692 frames in 5.0 seconds = 338.304 FPS
2295 frames in 5.0 seconds = 458.865 FPS
2480 frames in 5.0 seconds = 495.979 FPS
1614 frames in 5.0 seconds = 322.721 FPS
^C