Overclocking the X850 PE
Although the Sapphire Radeon X850XT Platinum Edition is clearly an extremely fast video card in its default configuration, we still spent some time overclocking it to see what kind of headroom was left in its core and memory. Armed with the latest version of ATI's Catalyst drivers with Overdrive Enabled, we set out to overclock the Sapphire Radeon X850XT Platinum Edition until we reached its maximum stable clock speeds. Due to the fact that this card is a "Platinum Edition", its default core and memory clock speeds are programmed for 540MHz / 1180MHz, but there is always some performance to be gained by overclocking...
When all was said and done, we were able to hit maximum stable core and memory clock speeds of 574MHz and 1.2GHz. These numbers represent a core clock speed increase of 34MHz and an increase in the memory clock speed of 48MHz. With the card overclocked, we re-ran a couple of high-resolution tests with 4X anti-aliasing and 8X anisotropic filtering enabled, and had some marginal boosts in performance. The Sapphire Radeon X850XT Platinum Edition's framerate in Aquamark 3, for example, jumped by about 3 FPS, or 5.8%, and Doom 3's framerate went up by about 2.5 FPS, or 6.2%.