ATI 9800 Overclocking
Tech Support Forum – Query on overclocking ATI 9800 Pro 128MB. _Another hat tip to google for this one._
You will want an over clocking tool such as (ATI Tool) this tool features an artifact tester to test your settings and if you want to wait, will automatically find your fastest settings with no artifacts for you. Let it work at night when you are asleep with “ATItool”:http://www.techpowerup.com/atitool/
This thing lets you find the “Maximum”:http://www.techpowerup.com/atitool/doc/quickstart.php automatically for both the core and also the memory. The main thing though if you want to overclock is cooling the card, so don’t expect much with the stock stuff.