How Does Overclocking Work?

By Ashley Poland

"Overclocking" refers to the practice of setting a computer component to run faster than the manufacturer's recommended. Computer hardware comes with an intended maximum speed -- such as 7200 RPM for your hard drive or 3 GHz for your processor. You can often exceed these recommendations with some minor tweaks to your BIOS settings. While it's usually safe, overclocking does come with some risks.

The Basics of Overclocking a Processor

Overclocking most often refers to increasing the speed of your computer's processor. The easiest method for overclocking your processor is to change the multiplier in the BIOS. The motherboard in your computer provides a base clock speed -- on most motherboards this is 133 MHz, though it may vary between manufacturers. Your processor comes with a multiplier, which multiplies the base clock to get the overall processor speed. On many processors, you can increase the multiplier in the BIOS to overclock the processor. If your processor is locked into its multiplier or doesn't have a lot of options, you can increase the bus speed for the whole motherboard. This approach is riskier, as it increases the speed of every component on the motherboard, not just the processor.

Overclocking Different Components

While overclocking usually refers to the act of overclocking a computer's CPU, it's not the only component that can be overclocked. For instance, you can overclock your RAM or graphics card to get more performance in specific areas on your computer. Even a monitor can be overclocked to provide a higher refresh rate than the default 60 Hz. Certain components, such as the hard drive, can't be overclocked; they already run at their physical maximum..

Benefits of Overclocking

Overclocking provides the performance of a more powerful chip without the cost of purchasing a one. Most users looking to get more utility from a computer are gamers or work with CPU-intensive programs, such as video or photo editing. Overclocking improves overall computer performance so long as it's done correctly and the system doesn't become unstable. You can even get extra performance out of some older computers with overclocking.

Risks of Overclocking

When you increase the speed of your processor, you also have to increase voltage so it gets enough power. This can damage your processor if you increase it too much. The increased performance of your overclocked PC results in higher heat output -- the stock fans that come with your computer can't always keep up. If you don't also add a more efficient cooling system or extra fans, you could end up overheating your computer. Overclocking can cause your system to become unstable, and even shorten the effective life of your components. If your computer is still under warranty, overclocking may void that warranty.