Hmmm, I just got Mirrors Edge and when I installed it and tried to run it I got a program is not responding error. I then found that there was nto Physx drivers here so I installed them. Mirrors Edge now works but the PPU does not activate ie the fan does not spin up. I've just tried UT3 and the fan does not spin up in that game either. I have set the Ageia card as the default in properties but that has not changed anything.... Is Nvidia pulling some shennanigans or what?
If I'm not mistaken, the newer PhysX games (Mirror's Edge, etc...) Only support the Nvidia GPU acceleration. As for Gears of War, that should still work just fine. Must be the drivers.
Did you try to check with the control panel to see what is enabled? Perhaps the driver's default is the nVIDIA CPU rather than an Ageia PPU
