It might seem odd to think about overlocking the BFG GeForce 6800 GT OC, since the card ships already overclocked. However, the .13 micron process used for the GPU core is the same used in the GeForce 6800 Ultra, which is clocked as high as 450MHz, so we knew we would have some headroom . BFG doesn't provide any fancy way to overclock its hardware, therefore we were left with using the widely available Coolbits Registry hack to raise the GPU and memory speeds. We found we were able to get as high as 435MHz on the GPU and 553MHz (1106MHz effective) for the memory. That's an impressive 65MHz increase for the GPU over the 370MHz speed that the BFG GF 6800 GT OC ships with, which was already 20 MHz over the standard version.
We went back and re-tested two of our benchmarks using the BFG GeForce 6800 GT OC, but now clocked at 435/553 MHz, so we could see what kind of gains we would get from these higher speeds. As you can see in the two graphs above, the gains were quite substantial. In Aquamark 3, we saw a 17% increase in performance and there was just shy of a 9% jump in the Comanche 4 Demo. The scores we achieved were some of the best we had seen, but one thing we should point out is that even though we got the large increase in Aquamark 3, the final score was just a shade higher than that of the non-overclocked Radeon X800 Pro. Still, we were quite impressed with the performance boosts we received when overlocking the BFG GeForce 6800 GT OC.