Ageia has posted two videos comparing an explosion in the PC version of Ghost Recon: Advanced Warfighter on a machines with and without the company's $300 hardware PhysX physics card. It's clear to see that the explosion is much more impressive on the PC with a PhysX card--the shrapnel and massive smoke cloud is entirely absent on the normal machine. However, there's some inconsistency in terms of the explosion's effect on the gameplay.

In the video without the PhysX card the screen doesn't shake and a nearby soldier is unaffected by the blast. In the video with the PhysX card the screen shakes relatively violently and the soldier dies (although he's slightly closer to the blast). Of course its possible that the second video could have been tweaked to further differentiate the two machine's explosion, but if simple effects like a screen shake requires $250-300 worth of hardware it's not hard to envision a lot of shakey gamers.