i have a Phenom X4 9950 BE @ 2.6 GHz and a GTX 470
when i got it i benchmarked it (3D mark vantage) and i got around 11k i OC the CPU to 2.8GHz and i got around 12k and then one more OC to 3.0GHz and it jumped to 16k score i did over clock the cpu more to 3.1Ghz and 3.2 Ghz but then the score difference was minor. i guess the GTX 470 was bottlenecked until my cpu reached 3Ghz
Yes, your cpu will bottleneck your GTX470. OC it a little bit, let's say 3.0GHz and you're good to go.