open a console an run
With my old on board video, I got 75 fps. With my nvidia, with the drivers, I get ~8000 frames/sec. Tuxracer now runs 1600x1200, 24 bit color at > 300 frames per second. I didn't even know that tux flapped his wings as the countdown starts. See if there is a linux driver for your video card at the manufacturer's site.