Originally Posted by jAkUp
you need a 100% DX9 card. And the 5XXX series is not listed under supported cards! How could this be? Quake4 is openGL!
It just means that it is recommended that you have a DX9.0c-class/high-end video card in order to run the game w/ maximum quality textures etc...
Interesting thought actually: Is there a difference in (OpenGL) IQ between running Doom 3 on, say, a DX8-class card (Geforce FX/Radeon 9***) and a DX9.0c-class card (Geforce 6, 7/Radeon X), like how a DX9 game (e.g HL2) will default to DX8 mode when running on DX8-class hardware? Or does OpenGL not work that way; is it merely a question of raw performance?