Comment 126 for bug 948053

12.04 32bit 3.2.0-31-generic-pae:

GL_RENDERER = Quadro4 900 XGL/AGP/SSE2
GL_VERSION = 1.4 (1.5.8 NVIDIA 96.43.23)

Prior to modifying the xorg.conf (created by: 'sudo nvidia-xsconfig & then modified by 'gksu nvidia-settings' my ~/.xsession-errors was continuously being flooded with:
/usr/bin/compiz (core) - Warn: No GLXFBConfig for depth 32
warnings.

I modified the Screen settings in the xorg.conf to include:
    Option "AddARGBGLXVisuals" "True"
Rebooted (just to be sure) & the messages are gone.

glxgears w/nouveau:
4005 frames in 5.0 seconds = 800.934 FPS
4248 frames in 5.0 seconds = 849.541 FPS
4240 frames in 5.0 seconds = 847.968 FPS
3910 frames in 5.0 seconds = 781.843 FPS

glxgears w/96.43.23:
13895 frames in 5.0 seconds = 2778.148 FPS
14700 frames in 5.0 seconds = 2937.791 FPS
14096 frames in 5.0 seconds = 2818.622 FPS
14580 frames in 5.0 seconds = 2914.800 FPS