How to Overclock Your CPU

How to Overclock Your CPU
Photo: Zii Miller, Unsplash
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Overclocking remains one of the most fulfilling hacks you can do to your home computer, but it’s not exactly something you can just jump into without any prior knowledge — though it’s certainly easier than it used to be. Here we’ll take you through the steps and resources you need to know about to get to grips with overclocking.

What is overclocking, anyway?

If you’re completely new to the term “overclocking” — or you’ve heard it before but don’t quite understand what it is — then here’s a real basic intro. Overclocking is essentially running the Central Processing Unit (CPU), the part of your computer that tells everything else what to do, faster than it’s supposed to go.

Even that definition isn’t quite right, though, because some processors do not come unlocked, which means they can’t be overclocked. Intel, for instance, signifies its overclockable processors with a ‘K’ or ‘X’ at the end of the model number. AMD, on the other hand, lets you overclock any of its processors.

Overclocking has become more accessible and more straightforward over the years. While any sort of overclocking adds an element of risk, as long as you proceed with caution and do your research, you can minimise that risk to a large extent. In other words, overclocking in 2020 doesn’t need the same sort of tech savviness or bravado that it did a few years ago.

The benefits of overclocking are just as you would expect: You get a faster, more capable computer setup, free of charge. On the downside, your CPU will draw more power and generate more heat, which will require liquid cooling, or a giant air cooler at the very least. If you don’t have the right cooling solution, you could shorten the life expectancy of your CPU and do damage to other components in your computer.

Overclocking is done at your own risk. It means you’re leaving behind the safety of stock speeds and configurations. You’ll almost certainly invalidate your warranty along the way. But for some, the risk may be worth it.

The overclocking toolkit

Screenshot: AMD Screenshot: AMD

Because of the heat and power implications of overclocking, it’s a practice usually reserved for Windows desktop PCs. While you could attempt to overclock all-in-ones, laptops, and even certain Macs, it’s not recommended (and often impossible) — there’s far less (if any) headroom to work with, and you need to really know your stuff if you’re even going to think about attempting it.

The overall speed of a CPU is determined by its base clock multiplied by its (aptly named) multiplier, so upping that multiplier is the most straightforward way of getting extra performance from the silicon. The overall speed of a CPU is determined by its clock multiplier, or what’s also known as the bus/core ratio. If you times the speed of the external clock by the clock multiplier, you get your internal clock speed. So a system with an external clock of 100MHz and a 45x clock multiplier will have an internal CPU clock of 4.5GHz. Overclocking via base clock adjustments allows for more fine-tuning, but it’s also more difficult and more dangerous, because of the effects it can have on the rest of the system. If you set the clock multiplier too high, for instance, your computer might not boot up.

Voltage adjustments can also be made on some configurations, adding more power to support a higher CPU speed. Like base clock adjustments, this is best left to the experienced overclockers, as the risk level and the threat of permanent damage to your hardware both go up. If you see options for the voltage, though, now you know why they’re there.

Besides a CPU that’s friendly to overclocking, you’ll also need a motherboard that is, too (and many now are). An aftermarket CPU cooler will usually be required, because the stock one that comes with with your processor is designed for temperatures generated by stock speeds. Which cooler you need will depend on your processor and how hard you want to push it. A bigger power supply might also be needed, so unless you’re building a system from scratch, be prepared to open up your computer.

Screenshot: Gizmodo Screenshot: Gizmodo

Overclocking is made much easier by the UEFI BIOS (or Unified Extensible Firmware Interface Basic Input/Output System in full) that operates modern PCs at the most basic level. Underpinning Windows (or Linux), the UEFI BIOS setting on your computer’s motherboard will feature overclocking options. It’s then simply a matter of nudging the speed up, checking the stability of Windows and the temperature of the CPU, and making any necessary readjustments.

Intel’s own Extreme Tuning Utility and AMD’s Ryzen Master can do the overclocking from Windows itself, if you don’t want to (or can’t) access the overclocking features you need from the UEFI BIOS. Meanwhile, programs such as Prime95 and Nzxt Cam are able to stress test your computer and work out if your current overclocking level is pushing the system too hard.

Any of these apps will work regardless of what CPU and motherboard you have, as long as they support overclocking. If you want to monitor more than just the clock speed, HWMonitor Pro will give you temperature stats of all your components, as well as allow you to monitor voltage levels, clock speeds by core, and record performance.

If you’re building a new system from scratch, then you’ll have a lot more options than if you’re trying to overclock or tweak an existing system, because you can buy components specifically designed for overclocking.

It’s possible to overclock the GPU (Graphics Processing Unit) inside your computer, too. Programs such as MSI Afterburner and Asus GPU Tweak give you full control over how fast your graphics card’s processor is working. You can nudge up both the memory and processor speed and then monitor the resulting temperature change. When you’ve gone too far, you’ll start to see graphical glitches or even system crashes. These tweaks are always done in Windows, whereas CPU overclocks can be handled in Windows or the UEFI BIOS, so they’re a little bit simpler to manage.

Finding help

So far, you have a very broad overview of how overclocking works. With the wealth of GPUs, CPUs, motherboards, and system settings out there, you’re going to need to do some of your own research before you get started. Looking for GPUs and CPUs known for overclocking is a good start, and then you can move on from there.

The good news for the budding overclocker is that there are a wealth of resources on the web to point you in the right direction. The overclocking community is a knowledgeable and friendly one, and there are plenty of hardware sites and forums where you can learn about overclocking CPUs and GPUs safely. You’ll also find plenty of good recommendations for software tools besides the ones we’ve mentioned here.

Be as specific as you can in your research. Look for advice from people who’ve used the exact same components as you, wherever possible, and check out the sort of setups they’ve put in place. Even if no one else has ever attempted precisely the same overclocking procedure you’re planning, chances are someone will have at least done something similar.

The Linus Tech Tips forums, Tom’s Hardware forums, and R/overclocking Reddit are excellent places to start looking for pointers and tips, and if you want to ask questions, the regulars are usually friendly. You’ll soon pick up knowledge from these boards even if you don’t understand every word and phrase straight away. At the very least, you can see what other people are trying and the software tools they’re using.

The software that comes with GPUs, CPUs, and motherboards varies, as do the associated overclocking options, but these tools are typically accompanied by plenty of documentation to help you figure out what’s what. The process will be easier (and more expensive) if you’re building a new PC, because you’ll be able to pick components with overclocking potential and overclocking features; if you’re trying to eke out some extra performance from an existing setup, your options will be more limited.