It took nearly two weeks, but on December 7th, 2011 a patch was released for Batman: Arkham City that `fixed` DX11 performance, but only for those running 64-bit versions of Microsoft Windows. Those running 32-bit versions of the operating system will have to wait for another patch that will come at a future date. We played the game on the patch with various card and while single GPU gaming in DX11 mode on Batman: Arkham City has greatly improved we did still find some issues..."
A quick patch update to Windows can extend the useful life of a PC. To take the fear out of Upgrading Windows 98 to Windows XP, rely on this guide. - PCSTATS Tips