The basics of overclocking

Overclocking your hardware is the final frontier of hardware optimization. You've bought your hardware, installed your OS, and you're ready to play. Except, you don't just want to run something at high graphics. You want ultra. You want at least full 1080p and 4k if you can get it. Not only that, but you want the highest possible frames per second possible.

Overclocking can push you to that next level, but you're worried. You've heard a lot of things about overclocking and a lot of them involve horror stories about melting your motherboard or CPU. The good news is, it's possible to maintain stable overclocking without destroying your hardware. In fact these days its relatively safe and easy to do. This article will focus CPU overclocking, what it is, and how to do it safely.

What is Overclocking?

Overclocking is the practice of forcing a specific piece of hardware to operate at a speed above and beyond the default manufactured rating. If you look at the specs on the AMD FX-8350,  you'll immediately notice the operating frequency is listed at 4.0Ghz. An impressive number by itself. Yet with overclocking it's possible to boost that performance even higher to 4.5 or even 5 GHz. This all depends on the CPU and your cooling system.

The AMD FX-8350 The AMD FX-8350


So how does overclocking work? To understand that you first have to know some basic terminology. Every CPU comes with two values that determine it's operating frequency. The first is known for Intel as the Base clock or BCLK, and for AMD as the Bus Frequency. This value represents the external clock cycle of your CPU. A clock cycle of 100MHz indicates that the CPU pulses externally 133 million times per second.

The second value is the Frequency Multiplier, which represents how many times the CPU cycles internally for every pulse from the external clock. As a result you can find out the operating frequency of your processor by multiplying the Bus Frequency by the Frequency Multiplier. A CPU with a Bus Frequency of 125Mhz and a Frequency Multiplier of 30 has an operating frequency of 3.75GHz. When you overclock your system you modify these values to increase your operating frequency above the factory's default rating.

How Safe is Overclocking?

Anytime you mess with your hardware's default configuration you are running a risk. So take into account the costs and the benefits of overclocking and make an informed decision. Overclocking is entirely optional. You really don't need to overclock your system if you're only using your system for casual gaming and office work. That aside, overclocking can be a safe and even fun way to get the most out of your hardware. So what are some of the reasons to actively pursue overclocking? Primarily I like to do it because it's fun. On a more practical note it's a great way to breathe some life into an old build, or to take a new build and supercharge it to the next level.

There are a few important risks to keep in mind when considering whether you should overclock or not. With a bit of caution, it's simple to mitigate these risks. The big value to keep an eye on is temperature. Overclocking your CPU means that it will produce more heat. More heat means expansion, and expansion can lead to CPU failure or even worse, a full meltdown.

Avoid this.  Avoid this.


Luckily overclocking technology has come a long way since the early days of CPUs. As long as you take small steps while searching for your ideal frequency, your motherboard will shut your system down long before you hit a level that can cause any real damage. Just in case, it's always important to keep an eye on your CPU temperature while you look for a stable clock. Technically a factory cooling fan will dissipate the heat from minor overclocking but if you want to do any significant tweaking it's highly advised that you look into more advanced cooling options.

A decent air cooling system is relatively inexpensive and can be a nice safety net if you're planning on doing light to medium overclocking I personally use a Cooler Master Hyper 212 EVO and I've maintained consistently low temps through extensive testing. Newegg TV even has a full breakdown on this fan and why it tends to outperform many of it's more expensive competitors despite it's lower price. 

If you're looking to get into heavier overclocking I suggest taking the extra step and going for full liquid cooling. The Corsair Hydro Series H100i is a fan favorite with over 1100 reviews. I've always leaned away from liquid cooling because of the simple complexity of installation but the H100i is ready to go out of the box and straight to your CPU.

So Where do I Start?

Everything you need to Overclock your CPU is within your Bios. Just remember, overclocking is an exercise of patience and research. It's important to sit down and look up information on your motherboard, CPU, and Bios so you know exactly what you're looking at long before you actually start changing settings.

You're also going to need some software to actually test and monitor your CPU before and after it's been overclocked, there are a lot of options out there but I'll list the one's I found most useful below.


Simple and Straightforward CPU-Z tells you everything you need to know about your CPU, Motherboard, GPU, Ram. All of it. In this case it's important to keep your eye on the values for Core Voltage, CPU Multiplier, Core Speed, and Bus Speed. If you modify any of these values in your BIOS they should show up. It's a good way to make sure the changes you made actually affected your build and didn't get reset back to previous values, as well as a way to know exactly what your new core speeds are.


CPUID is probably the most important program to have open immediately after setting up an overclock. This utility will give you information regarding the temperature of your entire build right down to case airflow and individual core temps. Ideally you'll want your CPU to be sitting around 40 to 50 degrees Celsius. You can technically run at temperatures up to 70 but you risk damaging your CPU if you go any higher and you'll often spike up to temperatures that will cause your system to flat out crash. Anything under 55 to 60 degrees during extreme load is the ideal butter zone for your final stability check.

Passmark Software (

Once you've actually set an overclock you're going to need to run a performance check to test for total system stability. I prefer Passmark over a lot of free products out there because it throws more than just linear tests at your CPU. It creates a high demand environment for every part of your build and forces your CPU to behave in ways it'll experience constantly during high intensity gameplay. Inevitably it'll expose most if not all system instabilities that could result from your overclock. Run it once before you start Overclocking and then again after you've applied some settings. Then check your results for even the slightest dip in performance.

I personally prefer an ASUS motherboard, the number of utilities and simple control you get over your overclocking makes it an easy choice. Newegg TV also has plenty of in depth guides for how to overclock ASUS Motherboards such as the one below.



Although this is quite a long video I highly recommend watching it through to the end. If you have an ASUS board from anywhere in the last three to four years your Bios is going to look almost exactly the same. The video itself explains nearly every important facet when it comes to overclocking using an ASUS motherboard and a lot of the terminology and concepts they explain can transfer to other motherboards.

Definitely take a much slower approach when increasing your core ratio multipliers. In the video they're linked up to a significantly hefty liquid cooling system and as a result they really weren't worried about overheating. When you're doing your overclocking overheating is going to be the first and last thing you check.

If you aren't running an ASUS board, Gigabyte is another great option. The video below will give you a chance to familiarize yourself with the BIOS associated with Gigabyte's Z97 motherboards. As well as show you how a highly experienced overclocker works within the bios. Additionally it's a cool chance to see how professional overclockers keep their systems stable during competition.

If you aren't running an ASUS or a Gigabyte Motherboard you should consult your manual for a basic guide through the BIOS and familiarize yourself with the layout. Usually keeping an eye out for things relating to CPU Voltage and CPU Multiplier/Ratio. These values might have slightly different names based on your manufacturer. If all else fails go slowly and carefully through each setting and change one at a time before you attempt to start your system. If something goes wrong you can easily restart, flip back to that setting and change it to what it was and go onward.

The Final Process

Overclocking your CPU must always be done with preparation and precaution. Once you know the basics of how to proceed, you'll use your BIOS  to slowly ramp up your CPU multiplier and your Clock Rate. Make sure to take it slow. Start with the base clock multiplier listed by CPU-Z and work up one or two values at a time. After every change you should save and restart your computer. Run CPU-Z and CPUID so you can observe your temperature and the new frequency.

Then run a Passmark test, keeping a close eye on your core temps throughout. If all goes well, shut everything down and load back into your BIOS to increase it by another small value. Rinse and repeat until you notice either an abnormality during the test or CPU temperatures getting out of hand. If it's simply a visual glitch you might simply need to increase the core voltage by a small amount. Just be careful not to push your voltage to close to 1.45 volts. Any higher and you risk damage to your CPU. If it's a problem with overheating you're probably at your max and you should drop it down a value and call it good.