Overclocking the Fatal1ty X800 XL
As we neared the end of our testing, we spent a little time overclocking the Abit Fatal1ty X800 XL 512MB using the clock frequency slider available within its proprietary vGuru application. To find the card's peak core and memory frequencies, we slowly raised their respective sliders until we begun to see visual artifacts on-screen while running a game or benchmark. But because this card also gives users the ability to tweak core and memory voltages, and fan speeds, we also upped those values to their respective maximums of 1.5v and 2.2v and set the fan to run at its highest speed...
When we were done with our overclocking experiments, we were able to boost the Fatal1ty X800 XL 512MB's core frequency to 430MHz and its memory frequency to 1120MHz. These are relatively small increases over the card's "xTurbo" clocks of 419MHz / 1094MHz, but please remember that Abit's xTurbo feature is already overclocking the card well over ATI's reference specifications.
While we had the card was overclocked, we re-ran the default 3DMark05 benchmark and also re-ran our custom Doom 3 benchmark at a resolution of 1600x1200, with 4X anti-aliasing and 8X anisotropic filtering enabled. As you can see, the overclocked scores are only nominally higher than the Turbo mode scores, but they are about 10% - 15% higher than the Normal mode scores.