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Avast Academy Performance Gaming How to Safely Overclock Your CPU on Windows

How to Safely Overclock Your CPU on Windows

Overclocking your CPU is a great way to make your PC run faster — without spending a cent on an expensive upgrade. Read on to learn how to push your processor to its limit, check your computer’s temperature, and achieve a stable overclock. Then, keep your CPU optimized with a dedicated performance booster.


Can I overclock my CPU?

Let’s start with the most critical question: Can you overclock your CPU? Not every processor supports overclocking. When it does, the CPU has what’s called a “unlocked multiplier.” 

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    One way to find out is to examine the name of your CPU. Intel adds the letter “K” to processors that can be overclocked, such as the Intel Core i7 9700K. Also, all processors from the Intel “X” series (used primarily for professional multimedia) can be overclocked. 

    On the AMD side, there’s nothing to worry about. All modern AMD Ryzen CPUs are “unlocked” and can be overclocked. If you have an older model, you can run a quick Google search to see if overclocking can be achieved.

    In theory, any CPU can be overclocked. But overclocking can be done only by raising what’s called the base clock — that is, the clock speed of your motherboard and your entire system (including the CPU, RAM, and PCI Express devices, such as sound cards or graphic cards). And just because you can overclock a CPU doesn’t mean you should. If you push the technology too far, you can expect to encounter CPU stability issues.

    The following sections explain how to benchmark your system to check the baseline performance of your CPU, stress test it, check the temperature, and — finally — overclock your CPU.

    Determine your CPU's core temperature

    Before you get started, it’s critical to check your CPU’s temperature, because overclocking will increase it — and you’ll want to measure the temperature change.

    Perform a system stress test

    If you aim to perform a serious CPU overclock, you should look at stress testing the CPU for a few hours. You want to be confident that your current system is stable under the current default clock speed. If you encounter problems later, you want to know why.

    My favorite tool for this use is Prime95. Again, check your temperatures as you’re going through this process (see the step above).Stress testing your CPUThis puts a constant 100% load on all CPU cores. Let it run for one or two hours and see what happens.

    Check your CPU’s performance

    Before you can recognize improvement, you need to know where you’re starting. You should begin by understanding your current CPU’s performance. One good tool for that task is Cinebench, which simulates a rendering workload. Extract the archive and fire up Cinebench Windows 64 Bit.

    Once Cinebench is launched, click on the Run button next to the CPU listing in the left panel. When the rendering is complete, it will show you the current score. Write that number down so you can refer to it later if you want to compare scores.Getting baseline Cinebench results for later comparisonAnother benchmark tool I like is 3DMark Basic, which is focused on gaming performance. As you benchmark, you should monitor your CPU’s temperature as mentioned above. Learn how hot it gets under this load.

    Before overclocking, you’ll want to make sure your PC’s current setup is dialed in. Avast Cleanup will automatically get rid of resource-draining apps to make sure your computer is running as smooth and fast as possible. That way, when you go to overclock, you’ll know that you’re starting from an optimal base.

    Access your BIOS

    Ready to get started? The only reliable way to overclock your system is to change the settings in your computer’s BIOS. The BIOS (sometimes referred to as UEFI) contains your PC’s key settings.

    To access the BIOS, you must turn off your computer and turn it back on. As the computer restarts, press the DELETE, F2, or F10 key repeatedly. Doing so allows you to enter your PC’s BIOS controls. The exact key combination varies by manufacturer brand and model. Usually, a message is displayed, something along the lines of, “Press F2 to enter Setup.”

    PC’s BIOS controlsYour BIOS likely looks different from the ones in these screenshots, but you should find some text like, Advanced CPU Core Settings or OC/Overclocking. This is where to find the settings to overclock the CPU.Using CPU multipliers to increase the clock speed

    Choose between automatic and manual overclocking

    Depending on the motherboard manufacturer, the BIOS may provide an Automatic Overclocking or OC Level function. These options give you a bit of an overclocking boost at safe levels, but the results usually are nothing special. That’s why we recommend going with the manual approach outlined in the next step.

    Adjust the CPU multiplier

    The first step to increase the clock speed should be to increase the multiplier. This uses the base clock built into the motherboard (usually 100 MHz) — multiplying that number yields your clock speed. For example, a multiplier of 36 (x100 MHz) gets you 3.6 GHz.

    Gradually raise the multiplier one step at a time. This is usually done by typing in the number or using the + key on the keyboard. Proceed slowly and treat this as an iterative process. Speed up your computer a little bit. Then, if all goes well, go back and speed it up some more. You can start by increasing the multiplier for one core and go slowly for the others. The more cores you overclock, the hotter (and more unstable) things become.

    Save your settings and reboot the system. Stress test and benchmark to estimate your CPU’s stability and performance.

    It’s important to note that overclocking the multiplier only gets you so far (in our case from 36 to 39) without things becoming unstable. That’s because your CPU requires a bit more “juice” to get going.Increasing the voltage under your UEFI / BIOS to support a stable overclock.

    To give it a bit more juice, find the CPU voltage setting. In your BIOS controls, this may be called CPU VCCIN, CPU Vcore, Dynamic Vcore, or simply CPU Voltage. By default, it usually is set to 1.25 or Auto. Increase this value slowly, for example to 1.4 or 1.5. This gives you a bit more room for overclocking, so you can try increasing the multipliers a bit more.

    But every time you overclock a CPU, your computer runs hotter. So make sure you have proper cooling!

    By increasing voltage and multipliers one by one, you’ll eventually find the maximum overclock on your system. 

    In this example, I gradually increased the clock speed from 3.6 GHz on a Core i7 5820K to 4.6 GHz by using a multiplier of 46 and a voltage of 2.1. Doing so improved the Cinebench score from 998 to an insane 1,317!

    Cinebench results before overclockingCinebench CPU test results before overclocking.

    Cinebench results after overclockingCinebench CPU test results after overclocking.

    That’s a performance improvement of 30%. Without overclocking, you might need to pay hundreds of dollars to achieve a similar speed increase!

    What happens if I get a black screen when I overclock?

    In some cases, your PC won’t boot up after an overclock. Don’t worry. Resetting the BIOS reverts all settings to their default values, so you can try the last setting that worked for you. Usually the motherboard has a button that says “Clear CMOS” or “Reset CMOS.”

    In the worst case, you can pull out the little battery on your motherboard, wait 10 seconds, and put it back in. Refer to your manual for more instructions.

    What does overclocking do, exactly?

    Overclocking allows you to run your processor at higher clock speeds than originally intended. This lets you do resource-intensive tasks faster and more smoothly, such as editing videos or photos or gaming. Generally, overclocking makes your computer feel snappier.

    In the example above, we went from 3.6 GHz to 4.6 GHz — quite an achievement! So that’s what overclocking does. Besides your CPU, you can also overclock your GPU.

    Why should I overclock my CPU?

    If you want more performance for gaming, rendering, coding, or simply for your day-to-day tasks, you can try to achieve a higher core clock. That saves a lot of money compared to the cost of upgrading to a new CPU or even a new computer.

    Is overclocking your PC worth it?

    Overclocking a PC is usually worth it if your computer is older or if the components are outdated. You’ll see greater results from overclocking older PCs, because performance will increase closer to the level of today’s more powerful components. You can always overclock newer machines, too, but performance gains may be more limited.

    Should I overclock my CPU for gaming?

    Absolutely! While many games are “GPU bound,” meaning that most calculations happen on the graphics card, a significant part of gaming performance also depends on processor performance. An overclock can give you more frames per second in many scenarios. But overclocking doesn’t help much if your OS and its programs aren’t properly optimized. To make sure no software or setting is slowing you down, check out our guide on how to speed up your PC.

    Is it safe to overclock your PC?

    Yes, overclocking your PC is totally safe. Overclocking means that you’re pushing your hardware beyond its official limits, but with modern materials, your hardware will likely have no problems. Though rare, the biggest risk in overclocking your system is CPU and other hardware temperature increases.

    But it’s almost impossible to “fry” your CPU by overclocking it. If the clock is set too high, your PC will simply reboot or bluescreen. As we mentioned above, it’s easy to revert to the original settings using the CMOS reset.

    But it’s important to remember that giving the CPU more voltage and higher clock speeds puts additional stress on it. That means that you'll reduce the CPU’s lifespan a bit. For example, you might reduce the CPU lifespan from 15-20 years to maybe 12-15 years, but it’s hard to say. You’ll almost certainly replace your computer before then anyway.

    If you’ve built your own gaming PC, we recommend overclocking with proper cooling in mind. For more on that, including our recommendations, check out our article on how to build your own gaming PC.

    Optimize your PC the easy way

    If you don’t want to risk it and just need an additional boost, you can also go the software route of optimizing your PC. At Avast, we developed a patented technology called Sleep Mode, which detects and disables resource-draining programs when you’re not actively using them.

    It’s best to put everything to sleep to get the maximum FPS out of your system. Download a free trial of Avast Cleanup, then go into the Speed Up section and look for Background and Startup Programs.

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