The reason you cant use a GFX 5200 for this game is because those are actually slower than GF4 TI 4200's! the lowest Geforce 4 TI! So if you have one of these cards you should have already killed yourself, hence you cant play DOOM3. Also the game is NOT DX9!!!! It requries it for sound and shaders but it IS an OPEN-GL game! ALL ID GAMES ALWAYS HAVE BEEN. And that is why it is sposed to run better on GFX's than radeons. BITCH