However, users of the NVIDIA graphics cards have one advantage - it is actually easier to overclock the NVIDIA graphics cards. ATI not only restricts the amount of overclocking that can be performed, they also failed (intentionally?) to include the option to adjust the fan speed.
In this guide, we will show you how to hack the fan speed of a Radeon HD 4800 series graphics card so that you can ramp it all the way up! Read more at TechARP.