The dirty truth all CPU's occasionally bottleneck GPU's, unless you play at 30 FPS.
What is your resolution? The GPU matchup is most closely tied to your resolution and target FPS than it is with the CPU. The CPU will determine your minimums in most games, and even the maximums if you use lower settings or have excessive GPU power.
I also find it interesting that everyone asks if the CPU bottlenecks their GPU, but never the other way around. A balanced system will experience both CPU and GPU bottlenecks depending on the game.