Using GLX_SGIX_pbuffer
7648 frames in 5.0 seconds = 1529.600 FPS
9436 frames in 5.0 seconds = 1887.200 FPS
9967 frames in 5.0 seconds = 1993.400 FPS
10054 frames in 5.0 seconds = 2010.800 FPS
11131 frames in 5.0 seconds = 2226.200 FPS
10423 frames in 5.0 seconds = 2084.600 FPS