The Catalyst 10.3 drivers promise performance gains in 3DMark Vantage, Aliens vs. Predator, Battleforge, CoD: World at War, Company of Heroes, Crysis, Crysis Warhead, Devil May Cry 4, DiRT 2, Enemy Territory: Quake Wars, Far Cry 2, Left 4 Dead, Left 4 Dead 2, S.T.A.L.K.E.R. Call of Pripyat and Cleary Sky, Resident Evil 5, H.A.W.X, Unigine Tropics, World in Conflict and Wolfenstein. The promised performance boosts generally range from 2 percent to 6 percent, but in some specific cases the gains can be as high as 15-30 percent.
Additionally, there are also some new features such as ATI Eyefinity enhancements and support for 3D stereoscopic glasses. You can read the full changelog below: