Mirror's Edge

We've already covered the way that Mirror's Edge uses PhysX, if you're not familiar. For our testing, we chose to play through a portion of the game that includes the long slide down the side of a building shown in the screenshot above. This segment starts out in a hallway, which you run through while a helicopter outside pours bullets in through the glass, shattering the windows and causing the blinds to warp and wiggle. Without PhysX effects enabled, the blinds aren't even there, and there are fewer shards of glass flying about. Once you're out of the hallway, the spruced up PhysX effects continue with enhanced bullet impact effects and the like.

Again here, Mirror's Edge looks great without the added eye candy, and sometimes the extra smithereens seem a little over the top. Generally, though, they're a welcome visual improvement.

The 9800 GT and 4770 are very evenly matched without PhysX enhancements in the picture. With PhysX enabled, the 9800 GT maintains decent frame rates, while even our fast quad-core processor isn't sufficient to keep the 4770 in playable territory. At least the 4770 was quick enough here to allow me to test. In some other areas of the game, leaving PhysX enabled with the Radeon card slowed performance to a crawl.