I used ATITool, my ATI tweaking utility of choice. I had read that this card offers a ton of headroom, and now I have confirmed it. I was able to reach overclock speeds of 595MHz on the core and 610MHz (1.22GHz) on memory. In case you haven't figured it out yet, that's almost a 50% overclock on the core and 25% on the memory!

Thanks to its generous factory overclock, you can expect the EVGA e-GeForce 7800 GT CO to outperform a reference clocked 7800 GTX at the most common playing resolutions and settings for many current games. If you crank the resolution beyond 1280 and turn AA and AF way up, then this GT won't best the GTX, but it will put up some really good numbers nonetheless.