as reported GLXGEARS run very bad, but the rest seems to work finely
GLX gears very slow but 3d game runs smoothly
OpenGL renderer string: GeForce 8800 GT/PCI/SSE2. $ glxgears Glxgears run really badly. It's very hard to move the window. Gears are stuck. $ torcs Torcs, 3D car game runs very smoothly and well.
OpenGL renderer string: Quadro NVS 320M/PCI/SSE2
Framerates around 4200 FPS for glxgears, but this week it did not bring the desktop to an almost complete crawl, though a little sluggish still.
OpenGL renderer string: GeForce 8600 GT/PCI/SSE2
Initially I had poor framerates but after logging out and logging back in I was not able to reproduce.