I recently bought a Sapphire Radeon HD 7950 to replace my older HD 5850 and get better FPS in Games like Battlefield 3 and others. What I did not expect though was that in one of my favourite Games, League of Legends, I get regular noticeable frame drops down to about 30 FPS from 60 FPS. With my old 5850 I did not have such problems, my Framerate never even dropped by 1 Frame. Strangely enough all my other Games work just fine, just LoL does not work properly.
I tried everything, from messing around with ingame options to trying the Beta Driver of Catalyst or reinstalling Windows and LoL. I just don't know what it could be else... Really tempted to give the card back and use my old one, I mean you could expect that at least League of Legends would work, and not be the only one that doesnt.