One of the Alien vs Predator’s marketing features for the PC version is the support for DirectX 11. In 2010 games were starting to add DX11 capabilities to the game engines. The game supports DX9 for XP and Vista users. See the page on game performance.
You can download the Aliens vs Predator benchmark for free from TechPowerUp.
Results are saved as a text file in “Documents” avp_d3d11_benchmark
COMPARATIVE GPU PERFORMANCE CHART
See the page that features a graph of the relative performance of video cards.