How to overclock your CPU without setting your computer on fire

Jayce Wagner

That old machine you built with your bare hands or plucked off a shelf at Best Buy might be holding out on you – through no fault of its own. Chances are your computer isn’t running as fast as it could – and not because of all those browser extensions and background processes. Nope, your PC might not be performing at its peak because it may have been hamstrung by manufacturer set speed limits.

How do you cast off those oppressive shackles keeping your CPU from its true potential? You overclock it.

Overclocking your CPU is about more than just juicing up your processor. It’s about exploring the limits of your PC, pushing it to perform at its peak.

Why is that? Well, when chips come off the line, they’re not uniformly capable. Due to variables in the manufacturing process, even CPUs produced in the same batch are going to perform differently.

So manufacturers like Intel and AMD test the chips and slap a speed limit on them based on a lot of different factors. Performance, supply quotas, and marketing all play a role in determining how many chips of a certain speed each manufacturer ships to retailers.

That’s where the fun comes in. By doing some tinkering, you might find that your humble CPU is hiding some serious horsepower. You could very well crank a 4GHz processor up to 4.5GHz or 4.6GHz for instance. With some serious cooling power, you might even push it to 5GHz. But your mileage will vary, because like we said, no two chips are alike.

Exciting, right? Depending on your luck, you might have a processor that is capable of running much, much faster than it currently is, like a caged cheetah. Or a surprisingly quick tortoise.

There’s only one way to find out.

A word of caution

When you overclock a processor a couple things happen. The chip runs hotter, and it uses more power. Both of those factors can be a problem if your PC has a barebones cooler.

If you want to get serious power out of your processor, you might want to invest in some high quality cooling. You don’t have to spring for full-loop liquid cooling if you’re just looking to squeeze out a couple more clock cycles, but you might want to have a look at high performance fans or other cooling solutions.

Secondly, if you’re looking for help overclocking your laptop, you’re probably out of luck. There are a couple laptops on the market which ship with unlocked Intel or AMD processors, but generally speaking most laptops – even gaming laptops – are shipped with locked processors.

Finally, overclocking your CPU usually voids any warranty your computer is currently under. So if you’re worried about your warranty, or your extended care plan, stop reading and back away.

Still want to give it a shot? Let’s get to the fun stuff.

Identify your CPU

First, it’s important to determine whether you can actually overclock your CPU in the first place.

This is an area where AMD and Intel differ significantly. Most AMD chips can be overclocked, while only two series of Intel chips can be overclocked.

Below are some current generation Intel processors which are unlocked and ready for overclocking. It’s not a definitive list, so if you’ve got an older PC your CPU, yours might not be down there.

SKU Default Speed Cores Price
Core i5-6600K 3.5GHz 4 $235
Core i7-6700K 4.0GHz 4 $340
Core i7-6800K 3.4GHz 6 $440
Core i7-6950X 3.0GHz 10 $1650
Core i7-6900K 3.2GHz 8 $1100
Core i7-6850K 3.6GHz 6 $610
Core i7-5960X 3.0GHz 8 $1016
Core i7-5930K 3.5GHz 6 $580
Core i7-5820K 3.3GHz 6 $340

Generally speaking, Intel chips can only be overclocked if they’re in the K or X-series. On rare occasions Intel produces an exception, like the affordable Pentium G3258. But that’s rare.

In contrast to Intel, AMD produces a lot of unlocked processors, and currently they have three different lines of CPUs that offer unlocked variants. Rather than list individual processors here, below you’ll find the three current series of unlocked processors from AMD.

Series Default Speed Cores Price Range
AMD FX Series 3.2GHz – 4.7GHz 4-8 $78 – $202
Athlon X4 K-Series 3.8GHz – 4.2GHz 4 $60 – $84
AMD A10 & A8 K-Series 3.8GHz – 4.3GHz 2-4 $79 – $392

Now, don’t worry if your CPU isn’t on either list. It can be tough to identify whether or not your CPU is unlocked, particularly if it’s an older model. Fortunately, the utilities used in this guide will let you know whether or not your processor supports overclocking.

Pop the hood

Overclocking doesn’t require you to open up your PC, but you should. Get in there and clear out any dust with a can of compressed air, as you want to make sure your PC is running as cool as it possibly can before you squeeze any extra clock cycles out of your CPU.

Open up your case, and be sure to blow out the main fan over your CPU, your GPU, and all the nooks and crannies. Your PC should be as clean as the day you bought it before you start juicing it for all its worth.

Get your tools together

It’s worth mentioning that there are two schools of thought when it comes to overclocking. Some prefer to overclock directly in your computer’s BIOS, while others prefer to use software you can run from your operating system.

There are advantages and disadvantages for both. Overclocking in the BIOS allows more fine-grain detail as you configure various settings. But this guide is for beginners, so we’re going to focus on using software.

You’ll want to to grab a utility that will allow you to make changes to your clock speed, and then test those changes. The app will help us determine what your PC’s stats currently are – how hot it’s running, how fast it’s running, and how much power it’s currently pulling down. The utility you need varies depending on if you have an AMD or Intel chip.

Overclocking Intel with the Extreme Tuning Utility

If you’re running an Intel processor, we recommend the Intel Extreme Tuning Utility, which you can download here. It’s a software suite Intel put together specifically for overclocking your CPU. Unlike some third party software, the Intel XTU is solid and reliable. It’s unlikely to cause any problems on its own, and it gives you a detailed look at what your CPU is currently up to. Also, it’s free.

Intel XTU has a lot of really granular options, and it’s going to be a little intimidating at first.

Intel XTU Main
Intel XTU Main

Don’t be intimidated, just take it all in.

There’s a lot here, so make sure you’ve got the time to pay attention. Overclocking is all about patience and incremental changes. You’re not going to jump right into the max clock for your CPU, you’ve got to ease into it and make small changes – test those changes – and then do it again.

If there’s one secret to successfully overclocking your CPU, it’s patience.

Intel XTU will tell you a lot about your system, and for that reason it’s a great little utility to have even if you’re not going to overclock your system. All in one place it lets you monitor your CPU load, your temperature, and run benchmarks.

Check your vitals

Right when you open it up, XTU will start you out on the “System Information” tab, where you’ll learn something very important. Can you overclock your CPU? Intel CPUs come in a couple different varieties, and most of them are “locked” meaning you can’t overclock them without some serious meddling. Take a look at the top of the XTU utility. Do you see this?

Intel XTU Overclock Warning
Intel XTU Overclock Warning

If so, it’s locked and cannot be overclocked with XTU. You might get lucky with the BIOS, but that’s outside the scope of this guide.

Before you do anything else, you’ll want to run a stress test. Using Intel XTU, click ‘stress test’ and choose a duration. Now, you can run it for any amount of time, but the longer the better – go ahead and plan on running it for at least an hour. That way, we can get a good idea of how your processor is currently performing.

Intel XTU Stress Test
Intel XTU Stress Test

Your computer will be running the stress test for an hour, but stick around. Go get a sandwich, but make sure you come back before the stress test is finished. The information we’re looking for here is going to show up during the test.

Down at the bottom of the screen, there are a bunch of line graphs and stats for your CPU.

Intel XTU Package Temp
Intel XTU Package Temp

What we’re really concerned with is the “package temperature.” How hot is your CPU running during the test?

If you’re running anywhere over 80 degrees Celsius, you should probably upgrade your cooling system before you overclock your CPU. Overclocking is going to get your CPU running hotter, and if you’re in the mid-80s you’re perilously close to causing damage to your system.

Ideally, you’ll want to see a temperature of 60 degrees Celsius or below. That will provide a good amount of extra cooling headroom.

Overclocking, a play in three acts

Open up the “Advanced Tuning” tab, and let us begin our dark work. There are two settings we’re going to use to overclock your CPU. Core Voltage and CPU Multiplier (also known as CPU Ratio). These steps are pretty interchangeable – if you’re running an AMD CPU, your tools will be different but your settings will look about the same.

Step One: Multipliers

Your CPU will already have stock settings for your multipliers, and they’ll probably look something like this.

Intel XTU Overclock
Intel XTU Overclock

Yours might look a little different, but we only need to pay attention to “multipliers” and “core voltage”

The multipliers or CPU ratios, will correspond to the speed you’re getting out of your CPU. For instance, a 32x multiplier means that core will cap out at 3.2GHz. Make sense? Now, increase those multipliers by just a couple points. Using the 32x example again, let’s increase to 33x. It’s not a big increase, but slow and steady, remember?

We want to see how your CPU handles just a little bit of overclocking first. Run the Stress Test again.

If it works, then go ahead and increase the multiplier by another step. Rinse and repeat. Eventually, the test will report a Fail result, or it will cause your computer to crash. When that happens, step back to the previous multiplier setting.

You’re not done yet. Often, the failure occurs because your processor is no longer receiving enough juice to enable its new level of performance. You can fix that by increase Core Voltage.

Step Two: Core Voltage

This is how much power your processor is currently using. Here we’re going to step things up little by little. This is important with Core Voltage. Directing way too much at your CPU is the easiest way to destroy it.

You can always Google around and see what settings other people are using for your CPU, and it’s not a bad idea to do that. Reddit’s r/Overclockers is a great resource to check in on what other people have gotten out of the same CPU configurations. But it’s not totally necessary for the kind of overclocking we’re doing here.

Remember, we’re all about increments.

Go ahead and increase your core voltage by about .025. It’s going to need a little more power now that we’ve increased our CPU multipliers. For example, If you’re starting at 1.250, we’re moving to 1.275.

This amount of increase is not a hard and fast rule. You can increase your voltage in a larger increment, if desired. But this increases the risk of damaging your processor.  As you increase voltage, it’s wise to consult online documentation for your processor to see the recommended maximum voltage. You might also browse overclocking forums to see the levels others have safely hit.

Before you hit “apply” make sure you wrote down your changes. Intel XTU will not save your changes if your computer crashes after applying them, it’ll revert back to default. So keep in mind where you were at before you hit apply.

Now, let’s hit it.

When you click “Apply” it’ll pop up a little warning, click continue and it’s done. You’ve overclocked your CPU.

Step Three: Once more, with feeling

Time to stress test again. This time just go for about five minutes. If your new overclock settings are unstable, XTU will give you a FAIL, rating or it’ll just crash out during the test. If that happens, scale back your changes and hit apply.

If you pass the test, do it all over again, starting at step one. Keep an eye on your temperature, don’t let it get too high, and you should be good to go. Once you’ve found the highest multiplier and core voltage that remains stable, congrats! You’ve extracted maximum power from your Intel chip.

Overclocking AMD with Overdrive

If you’re running an AMD processor, your steps are going to be a little different but the core principles remain the same. We’re going to increase two variables until we find a good balance.

Overdrive

AMD Overdrive is the software utility we prefer for wading into these waters. It’s reliable, and designed specifically for AMD processors. You can get AMD Overdrive here, along with some introductory information.

Once you’ve got it installed, head over to the “stability test” tab, and run it for about an hour, but don’t go anywhere – the information we need will show up during the test.

After about 45 minutes, take a look at the core temperature under “system status.” What we’re trying to find out here is how hot your CPU gets while it’s working its little heart out. If you’re at 80 degrees Celsius or over 80C, it’s not a good idea to overclock your CPU, at least not until you get some better cooling. If you’re around the low to mid 60s, you’ve got a little head room. But proceed with caution. In this case, lower is better.

Step One: Multipliers

First things first, we’re going to adjust your CPU multipliers. These are the controls that will alter how fast your CPU is running. Only move these up in small increments. What we’re doing here is trying to find the limits of how much power your CPU is currently drawing.

AMD Core Multipliers
AMD Core Multipliers

Move these guys up a little, by 1x at a time, and make sure “select all cores” is checked. Unless you really know what you’re doing, don’t bother with tuning individual processor cores. Just move them all up or down at the same increments.

Step Two: Core Voltage

Now that your CPU will be running faster, it’s going to need more power. The core voltage setting here determines how much power your CPU is getting, so once you’ve moved up your multipliers, move up your core voltage by one increment – by .025.

AMD Core Voltage
AMD Core Voltage

For instance, if you’re at 1.350, move it up to 1.375.

This amount of increase is not a hard and fast rule. You can increase your voltage in a larger increment, if desired. But this increases the risk of damaging your processor.  As you increase voltage, it’s wise to consult online documentation for your processor to see the recommended maximum voltage. You might also browse overclocking forums to see the levels others have safely hit.

Go ahead and hit apply, then run another stability test – this time for about one to five minutes.

Step Three: Rinse, repeat

Overclocking is all about patience. Now that you’ve overclocked your CPU, it’s time to do it all over again. Move things up one more increment, and keep an eye on your heat. It’s generally not a good idea to push your heat up past 80 degrees Celsius, so once you start approaching that temperature, it’s a good idea to stop.

What about BIOS?

We would be remiss if we didn’t address the elephant in the room: the BIOS.

You know that thing that you only dig into when something is going seriously wrong with your computer? The menu you can access by holding F2 while your PC starts up? That guy’s the BIOS. There you’ll find all the advanced settings for your PC, everything from startup settings, to boot disk, and yes, CPU clock.

In the BIOS, you’re changing the same settings that you are in Intel XTU or AMD Overdrive – the multiplier and the core voltage. But meddling with the BIOS is a little more dangerous than tooling around in XTU or Overdrive. The BIOS doesn’t have as many safety nets as those two utilities, so we wouldn’t recommend it for your first overclocking experience.