When the card first arrived site owner Nathan Kirsch spent an afternoon with the XFX GeForce 7900GS and overclocked the card using a Corsair Naultilus 500 water cooler and a Danger Den Low Profile Maze 4 GPU water block. When overclocked the memory IC’s were too hot to touch, so a 120mm fan was used to blow air across the video card to help cool the GDDR3 memory IC’s.
With a custom water cooler on the video card and a 120mm fan keeping the memory IC’s a little cooler the overclocking results were very impressive.
I (Nathan Kirsch) was able to reach 645MHz on the core, which represents a 195MHz increase in clock speed over a standard 7900 GS. This is a 43% overclock and one of the best overclocks that we have seen on any recent cores from both ATI and NVIDIA. The memory clock frequency went up to 840MHz when using Coolbits, but that honestly wasn’t far enough. The card would run night at day at 645MHz/840MHz never once showing an artifact. I went on to use Riva Tuner to further overclock the memory, but ran out of time as Brian needed the card to complete the article. 🙁
Before I handed the card over I did run some benchmarks and was pleased with the results. On my Intel Core 2 Duo E6700 processor and Intel Bad Axe D975XBX motherboard we were able to put down a stock clocked 3DMark06 score of 4590 3DMarks.
After overclocking the card back up to 645MHz on the core and 840MHz on the memory we were able to reach a much better score of 5810 3DMarks.
I never did find the max overclock on this card nor did I once see any artifacts during overclocked gaming and I did play Quake 4, Far Cry, Prey and F.E.A.R. with the card running at 645MHz/840MHz on top of the usual runs of 3DMark06. Our 43% overclock on the core did yield a 26% improvement in 3DMark06 performance and that alone is nothing to laugh at.