AMD Overdrive -- also known as ATI Overdrive in some products -- is a utility that allows you to customize your computer's video card or processor's settings and increase its performance. However, overdriving, otherwise known as overclocking, can cause damage to your computer, so you must agree to AMD's terms before all features will become available.
Enabling AMD Overdrive
After launching the AMD Overdrive or ATI Catalyst Control Center utility, the "Enable AMD Overdrive" or "Enable ATI Overdrive" check box is grayed out. You can enable it by clicking the padlock icon. This displays a window notifying you that any damage caused to the computer's components by overclocking won't be covered under the computer's warranty. Clear the message by clicking "OK." You can then click the "Enable AMD Overdrive" check box.
When used with a video card, AMD Overdrive and ATI Overdrive can raise the video card's processor and memory clock speed for higher performance or reduce their speed for lower power consumption. You can also reduce the fan's speed for reduced noise. Additional options are available if you use AMD Overdrive with your computer's processor, such as the ability to adjust memory timings when the utility is used with an AMD Black Edition processor.
Some novice users may be uncomfortable with making manual adjustments to a video card's processor and memory speeds. For this reason, AMD Overdrive and ATI Overdrive include an "Auto-Tune" button that automatically selects higher speeds and tests them for stability. The Auto-Tune feature removes some of the guesswork from overclocking, simplifying the process. However, through experimentation you can manually select a processor and memory speed combination that produces higher performance.
When you overclock your computer's processor or video card, it produces more heat than it would at its stock clock speed. In a computer with adequate cooling, this shouldn't cause concern. However, the increased heat can cause damage to these components. Although the chance is minimal, don't attempt to overclock a component you can't afford to lose.