NVIDIA just launched a new Forceware driver that unlocks PhysX with all GeForce graphics cards of the GeForce 8 series and up. Over at Fudzilla they did some quick tests with the new FluidMark PhysX test where they compare GeForce PhysX to AGEIA's discrete PhysX accelerator. The results are interesting in many ways. First of all, GeForce 8800 GT turned out to be a lot faster than AGEIA's physics processor and was clocked at 83fps with 4921 points, while AGEIA PhysX only hit 30fps and 1735 points.
But the most interesting discovery was that the performance took a drastic hit when the CPU was loaded with external work. The FluidMark performance dropped with both the GeForce card and the AGEIA PhysX card, but it was the graphics card that took the biggest hit when the processor was occupied with other things. The PhysX card dropped to 1282 points, about 450 points, while the GeForce card dropped down to 1344 points, that's about 3600 points less.
"It seems like the Geforce PhysX implementation is highly CPU dependent, and although some of this might have to do with the CUDA implementation, we didn’t expect to see the kind of performance drop we saw. It doesn’t bode well for PhysX in CPU heavy games and as yet we have no idea how well it works in GPU heavy games."
In other words, CPU-intensive games and other applications may affect performance quite a lot when gaming with PhysX activated, andone might very well wonder if NVIDIA is "cheating" a bit by letting the processor do parts of the work.
GeForce PhysX requires a lot from the CPU
Noctua
