What is overclocking? How to boost your PC's speed and power by changing its CPU settings

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• Overclocking is the process of forcing your computer to run faster than it's intended to go.
• You can overclock both your CPU and graphics card, which can help you run advanced programs on an older PC.
• Although overclocking is largely safe, it's possible to run into overheating and crashing issues.

Overclocking a component in your computer – usually the CPU, and occasionally the graphics card — makes your computer run faster than it was originally intended. This can improve your computer's performance without spending money to upgrade or enhance your PC. 

Overclocking is particularly popular among enthusiasts and gamers that want to get the most out of their high-end rigs or squeeze a bit more power out of an older system. Even some of the best gaming PCs can potentially benefit from overclocking their components, but the advantages of this practice on modern hardware aren't as dramatic as they used to be.

It's also important to remember that not every computer can be overclocked; the process requires specific hardware to be effective. And users should be aware that overclocking can push your computer to its limits and potentially shorten its lifespan. Here's everything you need to know about the risks and benefits of overclocking, and how to see if your computer can be overclocked.

What is overclocking?

Different computer processor chips run at different speeds — this is known at their "clock speed." A higher clock speed means a CPU can run more operations per second, and thus run your computer faster.

But even processors with different speeds are made with common components on the assembly line. It's only after the processors are built that companies test them for defects, take out the lower performing CPUs, and manually limit the clock speed of those chips to make them run slower in a computer.

That means that in theory, even these slower chips have the potential to run at faster speeds. This is where overclocking comes in. Overclocking lets you undo the throttling and run that slower chip at a faster speed, as if it were a less defective model.

To do this, you need to increase the processor's "multiplier," which can be found in your computer's UEFI or BIOS menu, causing the chip's clock speed to increase.

The pros and cons of overclocking

Overclocking is incredibly popular among computer enthusiasts, gamers, and anyone who regularly needs to run programs that take a lot of CPU power. This can include graphic design apps, 3D modeling programs, and more. Done right, it can increase your computer's performance essentially for free.

When you join discussions about building computers or buying graphics cards, you'll often find people talking about how easily their computers can be overclocked. Buying a less expensive graphics card that can be overclocked can save money, while still ensuring excellent performance.

In recent years, however, there's been some evidence that overclocking isn't as useful as it used to be. Modern CPUs already run so fast that overclocking can have little effect. And more important, improving your processor performance can be useless if the rest of your computer isn't fast enough to keep up. This is called "bottlenecking." 

For example, if you have a slow hard disk drive (HDD), overclocking your CPU won't improve your loading times. Likewise, games and other programs that use your graphics card more than the processor will see few benefits from an overclocked CPU. In those instances, you might see more improvements by overclocking your GPU.

Overclocking comes with some inherent risks. Companies don't throttle down processor chips for fun — they do it because the chip has defects, and running it too fast can cause issues with your computer.

Too much overclocking can lead to instability and crashing apps, as well as the occasional Blue Screen of Death, when Windows completely freezes and must restart to run safely. Frequent crashes can cause data loss and frustration. In some cases, overclocking can even damage your CPU or graphics card permanently.

You need to weigh the sometimes-marginal performance improvements that come from overclocking against these risks.

How to overclock your processor

If you want to overclock your computer, first assess if your processor supports overclocking – not all do.

Intel adds a "K" or an "X" to the model numbers of the Intel Core CPUs that can be overclocked. For example, the Intel Core i9-13900K can be overclocked, but the Intel Core i9-13900F cannot.

If you have an AMD CPU, the news is better – any "Ryzen" CPU can be overclocked.

Your CPU should have enhanced cooling if you plan to run it at a higher than normal clock speed. This means buying a heavy duty heatsink and multiple cooling fans. You might even want to use a liquid cooling system to deal with the extra heat generated by your faster CPU. 

To overclock the CPU, restart your computer and enter the startup menu in the computer's UEFI or BIOS. Usually you'll need to press F2, F12, or the Delete key at startup to enter BIOS or UEFI setup mode. These BIOS menus vary dramatically from one manufacturer to another, so you'll need to find the overclocking controls.

It's a good idea to increase the multiplier by a small amount, reboot the computer, and test it. You can increase the clock speed in increments to get to the speed you are interested in. Make sure to note your processor's original clock speed in case you need to return to that number.

Every time you increase the clock speed, spend a few hours "stress testing" the computer. You can use an app like Prime95 to temporarily run the CPU at 100% load and test your RAM to make sure there are no problems with the PC. The app Core Temp can help you make sure your CPU doesn't reach damaging temperatures while overclocking.

If your computer crashes, you get a Blue Screen of Death, or your programs won't open, return to the UEFI or BIOS menu and revert to a slower clock speed, or your original speed. 

It's also possible to overclock your graphics card's GPU, though you can't do that from the UEFI or BIOS menu. To speed up your GPU, you'll need to use an overclocking utility — one of the most common is MSI Afterburner.