Overclocking, in simple terms, allows computer hardware to run at speeds faster than the manufacturer intended. While overclocked, a computer's CPU or central processing unit (the electronic circuitry that executes computer program instructions), can do more tasks at once, render media faster or display video games at higher frame rates. However, the practice comes with the downsides of greater power consumption and heat buildup, and may be discouraged by manufacturers.
Every computer processor, be it a CPU or GPU (graphics processing unit) comes with a factory speed rating. This rating is a multiple of the clock speed, measured as a frequency in hertz. The clock speed of any given CPU is managed by its controller software, called BIOS. The clock speed measures the number of cycles a CPU can execute per second, measured in gigahertz, or billions of cycles per second. In 2021, consumer processors can commonly be found running between 2 and 5 gigahertz speeds. Older CPUs measured in megahertz, or millions of cycles per second.
Speed ratings are usually set conservatively by these companies because silicon production still does not allow two examples of the same processor to be 100 percent identical to each other. Imperfections on the microscopic level mean that each product on one assembly line will have slightly different capabilities. These variations also exist among each core in a multi-core CPU. As a result, chipmakers will lowball performance figures to keep uniformity among product lines. The true performance threshold of these processors is locked away in the BIOS, but it can be accessed through the process of overclocking.
Overclocking a computer's processor or CPU allows it to exceed factory speed limitations and complete tasks faster than normally possible. Other types of hardware, like GPUs and RAM, can similarly be overclocked for even greater boosts in performance.
While forcing your old or low-budget computer to run as fast as the more expensive stuff can sound like a fantastic proposition, for inexperienced users, overclocking may lead to its own issues. It's not a cure-all technique and works best in PCs with upgraded hardware.
If you want to try doing it, we have some advice below:
How to Enable Overclocking
First thing, check if your particular processor is able to be overclocked. Many consumer-grade chips, especially those in laptops, have this feature permanently locked away. You can check your CPU's exact model designation in Windows by opening the Task Manager (CTRL+SHIFT+ESC), clicking over the Performance tab, and finding it listed just under the CPU section. The manufacturer's website will likely be the best resource for finding the exact specs and features of the component. (You can also see your processor's current speed under "base speed" in the bottom-right of the Performance tab.)
Make sure your system is clean and dust-free, as dust will exacerbate overheating and performance issues.
Once you've confirmed that the chip can be overclocked, there are a few paths to enabling it in your operating system. The old-fashioned way is to go through BIOS, but there are now software assistants available from Intel and AMD, which can control a compatible CPU from the desktop. They also handily monitor clock speed, power consumption and device temperature. Intel's client is called the Extreme Tuning Utility (XTU), while AMD's is the Ryzen Master Utility. Follow either of those links for more instructions on installation and setup.
If you would rather boot your PC into the BIOS menu, it can be achieved on Windows 8 or 10 by hitting the designated "hotkey" just as the computer boots up. This key varies by manufacturer, but is often either F1, F2 or Delete. Windows 11 owners should instead press Escape right at startup, then F10 to enter BIOS.
Users may find their hardware boots up so fast that it makes timing the hotkey press difficult. In such cases, there is a lengthier alternative method.
- On Windows 10: Navigate to settings under the "Gear" icon in the Start panel.
- Select Update & Security > Recovery > Advanced Startup > Restart Now
- Upon restarting, you'll encounter a special boot menu.
- Select Troubleshoot > Advanced Options > UEFI Firmware Settings > Confirm Restart
- Your BIOS will now open.
- Navigate to the CPU section of the BIOS. Select an option called Processor Settings, Overclocking or OC.
On Windows 11, the process is mostly the same, except Recovery is found under System instead of Update & Security.
In either the BIOS or your software client, there will be two important settings: CPU Multiplier and CPU Voltage.
The CPU Multiplier is the virtual "clock" that your processor syncs to. By default, it's probably set to 100 megahertz. Bump that up to 200 megahertz and finish the boot process to begin overclocking. After confirming that the system is running stably, you may consider increasing clock speed by additional 100 megahertz increments. Intel's XTU provides benchmarking and stress testing apps to verify stability at each configuration. Keep a close eye on system temperatures throughout the process. If you find your CPU exceeding 175 degrees Fahrenheit (80 degrees C), then it's probably time to dial speed back, or start upgrading fans.
CPU voltage controls how much electricity goes into the CPU and will be set around 1.25 volts by default. For beginners, we recommend leaving this setting alone, as increased voltage can easily lead to overheating. For many chips, drawing more than 1.5 volts can cause permanent damage, so a tiny adjustment goes a very long way here. With proper cooling and power supply upgrades, voltage can be increased in .05 volt increments for further performance improvement.
Drawbacks of Overclocking
The faster a computer runs, the more power it will consume, possibly overwhelming the stock power supply. A power pack that draws more current than it's rated for can eventually enter a failsafe state and force an unexpected shutdown. Before overclocking, check the specs written on the power brick that either plugs into the outlet or is integrated into the PC. If it's a relatively low current rating like 65 watts, you might want to upgrade to a 125-watt unit or higher.
As the CPU soaks up more energy, it also lets off more heat. Overclocking for extended periods will bring excessive heat buildup, which in turn can lead to lower performance or crashing. Worst case, it can cause components to fail prematurely, so heat management is vital while overclocking. Consider installing larger and/or faster fans to cool the hardware and keep it running smoothly. Extreme performance seekers also can look into building a liquid cooling system. These are more complex than typical air cooling, but are also able to dissipate heat more efficiently in many cases.
As with all machines, processors are subject to thermodynamics They will consume power and expel heat at a greater than linear rate to speed gained. At higher frequencies, a CPU will eventually hit what's known as a "power wall," where performance returns diminish past the point of being useful. For this reason, chipmakers have de-emphasized clock speed in recent years, instead relying on multi-core processors which can run much more effectively than the fastest of their single-core ancestors.
Manufacturers' Overclocking Policy
In recent years, Intel and AMD have started to embrace overclocking, providing their own resources and software to make the process easier (see sidebar for more on this).
"Intel offers unlocked 'K' SKUs for users who want to overclock their CPUs for even more gaming power and performance," says Intel's technical PR manager, Bennett Benson. "When paired with an appropriate unlocked chipset, users can adjust the power, voltage, core, memory settings and other key system values for even more components through overclocking." However, he adds, "Altering the clock frequency and/or voltage outside of Intel specifications may void the processor warranty and reduce the stability, security, performance and life of the processor."
Intel used to offer a "no questions asked" extended warranty called the Performance Tuning Protection Plan. This policy expressly covered any damage caused by overclocking, but it was suddenly discontinued in March 2021.
On the AMD website, the company notes that "overclocking a component beyond its specified operating threshold can, among other things, cause a system crash or hang due to overheating the CPU or other system components. Any system crash or hang can result in the loss of data. Any operation of the CPU beyond its specifications will also void the product warranty."
In other words, manufacturers are unlikely to honor a replacement warranty if they find that component damage was specifically caused by overclocking. Increasing clock speed conservatively probably won't cause atypical wear on its own, but you should be prepared to assume the risks inherent to overclocking once you activate the feature.
Should I Overclock My PC?
Before attempting to overclock, pay close attention to your computer's performance in the task manager, and where it seems to be lacking. If it's constantly maxing out memory, then a simple RAM upgrade will solve more issues than overclocking will. If you see your CPU running at near-max capacity under normal use, then a new processor might be in order. The performance gain of overclocking will be marginal compared to installing a new processor with more cores, but it can also be done for much cheaper.
New technologies like multi-core CPUs and Turbo Boost functions have perhaps made overclocking unnecessary for the average user. Right out of the box, a modern processor will lay down performance that tech junkies a decade ago could only dream of. Still, this technique can be great for squeezing out some extra speed during gaming or media rendering. Just be sure to install supporting power supply and cooling upgrades if you're planning to make a regular habit of it and stay up to date on your manufacturer's warranty policies.