I didn't understand what you said, until I tested the mod of the config file, mentioned above. Sadly the performance goes down by a lot. Don't know if me using vsync has anything to do with it. For anyone interested, this is the kind of performance difference we are talking about. Haven't seen it in since Wolfenstein on my old 7950. Edit: Seems if I use framebuffer instead of viewport as the coordinate space, no more slowdowns occur.