Bear in mind that according to the release notes, AMD Crossfire support for Batman: Arkham Knight is currently disabled while AMD works closely with Warners Bros. Interactive Entertainment in resolving the issue. There are also couple of known issues where the game crashes during in game benchmark or while exiting the game and where the screen turns black or pink while changing the resolution to 1680x1050.
Unfortunately, Batman: Arkham Knight game is plagued by numerous other issues on the PC, on both Nvidia and AMD hardware, including a 30FPS lock, which can be fixed via config file, stuttering, lousy optimization, crashes and plenty of other issues.
The new Catalyst 15.6 Beta driver is available for Windows 7 and Windows 8/8.1 in both 32-bit and 64-bit version and can be found at AMD's beta driver siteAMD's beta driver site.
