VBLANK SYNCING Setting the environment variable __GL_SYNC_TO_VBLANK to a non-zero value will force glXSwapBuffers to sync to your monitor's vertical refresh rate (perform a swap only during the vertical blanking period) on GeForce or newer hardware (ie: everything but TNT/TNT2 products). Make sure you set it in the xterm you're running the game from. Hope this helps... --andy