It's apparent that the CPU is a massive bottleneck when it comes to physics, or PhysX specifically, as we wound up with very consistent lackluster results of around 30FPS.

The chaps over at Techgage posted an in-depth look at NVIDIA's PhysX, both from a status and technical standpoint. Here's a taster:

In the three full years we've been following the progress of PhysX, it doesn't seem to have moved too far. We kept hearing promises of PhysX-equipped PC games, but the only ones to actually see the light of day have either been canceled (Auto Assault) or were more of a tech demo than a real full game (Warmonger, Cell Factor). Other than that, most of the support has been seen in console gaming. AGEIA needed PhysX to be picked up by a company with deep pockets in order to see their technology truly succeed, and I think we are on the right road now.

As it stands, Unreal Tournament III is the only game that supports PhysX with the help of NVIDIA's latest GPU and PhysX driver. We've been told that more support is on the way, but I'm not sure what games would be included. As mentioned before, most of what we've seen so far have been not much more than tech demos, so whether or not Warmonger and Cell Factor will be supported, I'm unsure. It wouldn't be much of a loss, though. Ghost Recon is one confirmed to have support added, however, so fans of that series can rest easy. As for upcoming titles, the names are far from plentiful, but now that PhysX is fully supported on the GPU, adoption is sure to look more appealing to developers all over. Backbreaker is one title in particular I've seen from AGEIA in the past, which is simply put, a PhysX-enabled football game. From what I remember, the physics were really amped up here, and colliding players looked incredibly realistic.

With these new drivers, support is added for PhysX on NVIDIA's three top-end GPUs, the 9800 GTX and GTX 260 / 280, but where's the rest of the support? For whatever reason, support for other models took a little more effort, but they are not forgotten about. We should be seeing new drivers next month that will open up support for all of the 8-series and 9-series GPUs. But another predicament arises. Because PhysX slows down gameplay, and requires a fair amount of your GPU power to run, do you really want to enable the feature on lower-end models? It might all depend on the game and resolution, but if support is built in, it will cost you nothing to test it out and see if it works for you. Like gaming in general, the faster the GPU, the better it will be able to handle physics calculations without much of an FPS loss.

In my tests, the 9800 GTX suffered in losing 10FPS off of what the PPU could help with, but it might be that the GTX 260 or GTX 280 would portray differing results. There's no two-ways about it... those cards are powerful, so I have a feeling that running PhysX off of them would affect your overall FPS a lot less than what we saw here. But even as it stands, for our GPU which retails for around $230, our game ran 66% faster with running the calculations off the GPU over the CPU. These numbers should only continue to improve, as the GPUs become more powerful and the number of stream processors increase.