I get 155 FPS on an Nvidia FX5600 128MB card, with the open source nv driver, so your are doing pretty well really...My PC: Athlon XP2000+, Matrox G550 AGP card (32Mb gfx RAM). When I ran glxgears under FC4, I got about 1200 fps. After upgrading to FC5 and the new xorg, I get 600 fps.
I know if I use nvidia's driver it might be x10- x20 that value. DaveT.