Cant tell you just by looking at specs because it depends what you are doing and what resolution you are running at. Record what your FPS is at your current settings, then to see what the CPU limited FPS on a game is lower all graphics settings except particles and physics to lowest, find out what your FPS is. If the FPS doesnt change at all then your CPU is bottle necking your graphics card, but normally the GPU is the limiting factor but as long as you are still getting over about 40-60FPS then it doesnt really matter.
i think u r right..
my brother got phenom n 5750 n got better fps on battlefield 2, we both play @1080