Regardless of how fast graphics cards become over time, nearly all of us in the enthusiast set are plagued with the flaw of never being satisfied. If there is even the most remote chance that a piece of hardware could be faster, we'll scour the earth searching for a way to unlock that speed. Fortunately, graphics card vendors have provided users with the appropriate tools within the drivers to push the envelope with their hardware and attain the highest framerates possible. Using these tools, we threw caution to the wind and attempted to find the breaking point for each of the major GPU's of interest. Keep in mind that we are dealing with reference card samples here and not actual retail products. As such, your mileage will vary when attempting to overclock your own graphics cards.
The Radeon X1800 GTO comes equipped with a stock core frequency of 500MHz. Thanks to its 90nm fab process, it seems certain that there should be some solid overclocking headroom with this GPU. Furthermore, the conservative stock 1GHz memory frequency had equal opportunity of seeing some more aggressive speeds. After experiementing with gradually increasing clock speeds for both core and memory, we settled on a stable overclock of 575MHz for the core and 1.13GHz (565MHz DDR) for the memory. As we see in the Quake 4 benchmark results shown above, this overclock was able to provide an additional 4fps. Were one to experiment with an aftermarket heatsink assembly or utilize watercooling, they could easily squeeze some higher frequencies from this card and see larger performance increasese.
With NVIDIA's latest GPU's also sharing a 90u process, it is no surprise to see some equally impressive numbers regarding their overclocking ventures. Again, we find modest to impressive performance improvements ranging from 3fps up to 9fps. When you consider the fact that these performance increases for all cards are coming free of charge, the notion of overclocking becomes less of a tainted black art and more of a worthwhile venture.