Unlikely. Any performance gain would be at the expense of quality and/or WHQL certification. ATI has an army of engineers and has spent years and millions of dollars developing drivers and if they could gain anything over the competition simply by changing a few settings they would make them available via the CP, if not the default. To squeeze more juice, overclock... perhaps beyond what ATI might offer for the XT with a third-party proggy like ATI Tray Tools. If you are slightly more daring, replace the cooler with something like the Zalman V700.