Use Caution when overclocking.
My X800Pro modded to 16 pipes and running faster than an X800XT (550/500) scores about 6300 in '05 at very stable settings but after hundreds of gaming hours it's starting to die. I installed the Zalman VF700-Cu GPU cooler and dropped the temps significantly so it runs cooler than 60C under heavy load while overclocked but it may be too late....
The Zalman cooler does not allow significantly higher overclocks but it does keep the temperatures safely low when running it at overclocked settings and I highly recommend this cooler for any video cards that come with a modest stock cooler even if you don't overclock. If only I had purchased one sooner. Clearly there is a reason why 16 pipe X800XT cards, which are essentially the identical R420 card to a 12 pipe X800Pro, come with bigger stock coolers.
Well, at least I can send this card to a light duty computer before it completely dies and get myself something newer now.