I guess none of us are playing L4D2 on Linux yet, but:


FEATURE HIGHLIGHTS OF THE AMD CATALYST 12.11 BETA8 DRIVER

AMD Catalyst 12.11 Beta8 is now available, and includes the following updates:
(Please note that AMD Catalyst 12.11 Beta8 includes all of the fixes found in previous versions of AMD Catalyst 12.11 Beta)

Improves performance up to 5% in Max Payne 3
Includes single GPU performance updates for Far Cry 3
Improves CrossFire scaling for Planetside 2 (Crossfire scaling is still limited to ~30% at 2560x1600)
Resolves the Skyrim lighting issue (missing a lighting pass) for the AMD Radeon HD 7900 Series
Resolves the hang encountered playing Dishonored on the AMD Radeon HD 6000 and AMD Radeon HD 5000 Series
AMD Catalyst 12.11 Beta 8 for Linux includes significant performance improvements for Left for Dead 2


http://support.amd.com/us/kbarticles...etadriver.aspx