Your bottleneck is your GPU. I have the Q6600 (G0) @ 3.2 GHz and a 6950 HD 2GB and BF3 on unltra with a res over 1080 on a 27" monitor. My cpu runs 60% and the GPU runs at 98%.
You should be able to get 3.0 GHz without changing the volts. You may have to update your BIOS to fix your ram issue.