Hi
The resolution you play at will be a factor in determining whether or not your Q6600 will be a bottleneck.
Lets say you play at 1080P or below I'd say your Q6600 will bottleneck either card on both BF3 and COD, an overclock will help, most Q6600's can reach about 3.4Ghz which may not lift the bottleneck completely but should definitely give you playable FPS.