There definitely IS the phenomenon of CPU bottlenecking. Its just not as bad as it was a few years ago when most people were on lower res screens. However, it can still be seen in certain games even at 1920x1200 as this review has shown (Anno 1404, and to a lesser extent FC2). For most it will not be felt, esp if over 60 fps, just as you will not feel any difference between a 7970 and a 6870 in many games. I have a feeling several other (not tested) games like Skyrim, Starcraft 2, GTA4 may show similar results to Anno 1404. Its probably unanimous that multi-GPU bottlenecking occurs more severely depending on the CPU.