We used the full retail version of Prey, patched to version 1.3. All in game settings were set to their maximum apart from anisotropic filtering and anti-aliasing, which we varied for different portions of our testing. Our benchmark is based on a custom demo recorded in the Salvage level which, being indoors, doesn't use a lot of transparent textures so turning on transparency anti-aliasing shouldn't affect performance very much.
We ran our tests twice, once with transparency anti-aliasing and once without to see how this advanced AA technique affected performance. The lighter bars represent our results with it turned on.