Overclocking Safely Article

How to Overclock Safely

What is Overclocking?

Overclocking is the act of increasing a component’s clock rate, which essentially means you’re making it run it at a higher speed than intended. This usually applies to your computer’s CPU or GPU, but it is possible to overclock other components as well.

Increasing any component’s clock rate will cause it to perform more operations per second, which in turn will cause it to produce additional heat. Overclocking will allow you to get a little more bang for your buck in terms of performance, but your components will require additional cooling and care.

CPU Overclocking Overview

Your computer’s CPU comes from the factory set to run at a certain maximum speed. If you run your CPU at that speed with proper cooling, it should perform fine without giving you any problems. Despite this, you’re not always stuck at that specific CPU speed. You can modify your CPU’s clock speed in the computer’s BIOS, forcing it to perform more operations per second.

This will allow you to speed up your CPU, which can speed up your computer assuming your computer is limited by the CPU that you’re using. This will also cause the CPU to produce additional heat. If you don’t provide additional cooling, it’s possible it will become damaged, or even become unstable and cause your computer to crash or restart.

It’s possible you won’t even have the option to overclock your CPU. Quite a few motherboards and Intel CPUs are shipped with locked speeds, preventing you from altering or customizing their preset values or overclocking your CPU. Intel sells a decent bit of CPUs with unlocked defaults, geared towards computer gamers that want to overclock and use every bit of power they possible can out of their CPU. Look for CPUs with “K” in their model number. This is how Intel distinguishes their cards that are unlocked from those that are locked.

Check CPU Stability and Stress Test

To be careful and make sure that your overclock is done successfully, you need to find out if the CPU is stable at idle and max load. To find this out, you should use a highly regarded software named Prime95. You should also download another program so that we can monitor the temperatures your CPU is outputting. For the purpose of this tutorial, you should download a program called Core Temp, because this program will work with both AMD and Intel processors.

Once you have these programs installed, open Core Temp and begin monitoring your CPU's temperature. You should always look at the lowest core temperature to allow yourself to get a good understanding of how hot your CPU is actually running. After this, you’ll want to benchmark your CPU at stock, and see how hot it runs at 100%.

Open up Prime95 and select the "Just Stress Testing" option, and then you'll be greeted with a list of options of stress tests to choose from. Choose the "Blend Test" option, and click "OK".

Open the BIOS

After about 10 minutes, once your temperatures have become stable, open up Prime95 again. Select the "Test" option on the top bar and hit "Stop". After you do this, you’ll want to restart your computer and press whichever key on your keyboard it shows you to get into your BIOS. The UEFI (Unified Extensible Firmware Interface) you see will be specific to your brand and model of motherboard, but the terms used should always be the same.

More experienced users will probably find manual control more in-depth in regard to typical overclocking. To keep things simple, you’re going to want to change the CPU ratio, or multiplier if that’s the term your BIOS uses, for all of your cores to the number you’re looking to achieve.

Test Max Load and Limits

Once you've increased the CPU ratio multiplier, you’ll want to save the changes and exit the BIOS. Now boot into Windows and open up the Core Temp program so that you can monitor your CPU temperature. After this, open up Prime95 and navigate to “Options" > "Torture Test" > "Blend Test" to and see how your chip handles max load. If it remains stable for about five minutes, you can begin to incrementally increase the multiplier to overclock it further.

Once you’ve reached this point in the overclocking process, you’re going to want to slowly raise the multiplier by one, and then repeat the process of stress testing in Windows. You should keep doing this until you reach the point where you boot and get a BSoD (Blue Screen of Death), or your CPU begins to throttle itself thermally. Hopefully you receive the blue screen before your thermal limit is reached.

Increase Voltage

Now to deal with the blue screen issue if it’s present, you’ll need to work with your CPU’s VCore voltage. In the BIOS, you’ll want to find CPU VCore Voltage Mode. Find and select the "Fixed" option. Once you’ve reached this point, you might need to do a bit of extra research to find the stock VCore your CPU takes, as well as what people suggest for overclocking your specific CPU.

At this point you’re going to want to begin slowly increasing the voltage by .01 volts each time. Do this until you’re able to successfully boot your computer, run stress tests and maintain stability at your specified frequency. Once you’re more comfortable with overclocking, you will be able to increase voltages by .05 or 0.1 at a time. Learning how to overclock your CPU is all about learning how your CPU will responds to different amounts of voltage.

Once you reach the point where you’re unable to reach that next frequency, regardless of how much voltage you supply it, you’ll want to dial back your overclock by 0.1GHz and lower the VCore voltage to the last stable settings for that frequency and maintain it there. This will be where you stop your overclock.

GPU Overclocking Overview

Just like CPUs, overclocking can get you great value for your money, but it won’t be as easy as pressing a couple of buttons and jumping right into a gaming session. Very similar to overclocking your processor, overclocking your video card is going to take time and patience for you to do some stability testing, and is risky if not done properly. If you follow this guide, however, you’ll be okay.


Before you get started, you should head to Google and get some information about your card. Check relevant sites such as Overclock.net to see what clock speeds others are receiving. Don’t just jump right in, apply these clock speeds and start benchmarking. It’s important to remember every card is different. Two people with the same exact same model card can get two different overclock results. This research is simply to find out what other people are getting so you can see what ranges are reasonable. While you’re on this step, you should also find out what the highest safe voltage for your card is.

Run a Benchmark Test for Your Card

For this step you’re going to want a program called MSI Afterburner. Once you have this, open it up and be sure to take note of your stock speeds. Before you get started overclocking, you’ll want to run Heaven (Which comes with MSI Afterburner) one time fully, just to make sure your card is stable at stock speeds. You will also receive a benchmark score, which you can use to measure your progress as you overclock. Here's what you’ll need to do:

  • Start Heaven, and the initial settings menu will appear.
  • Tweak the settings as you see fit. Typically, I’ll set Quality, Tessellation, and Anti-Aliasing to the maximum value, because my card is mid to high range. If you're going to be overclocking a lower-end card, you probably won’t need to set these settings so high. Be sure that Resolution is set to "System."
  • Click on the Run button. This will cause Heaven to start cycling through scenes designed to push your graphics card to its absolute limit. It doesn’t matter if it seems distorted or buggy, that's what we’re looking for.
  • Now click on the "Benchmark" option in the top left-hand corner of your screen to run a benchmark test. This will cause Heaven to go through all the scenes one time, while measuring your card's performance.
  • Once this benchmark is complete, you will see a little window with your score on it. You can write this down and compare it with your scores as you go through this process.

If your card successfully makes it past the benchmark run, you’re in the clear! Your card is stable at stock settings.

Raise Clock Speeds

Now that you’ve done the proper research, you can start overclocking. Launch MSI Afterburner and slowly start raising your core clock by about 10MHz or so. Select apply to apply these settings, and then make sure that they were successfully applied by checking GPU-Z and making sure that it matches. Make sure you also save in MSI Afterburner, and assign the new settings to a profile.

Now you should open up Heaven again, and click on the Benchmark button. If this benchmark runs without any issues, your overclock can be considered stable and you can raise the core clock by 10MHz again.

Eventually, you will encounter some issues. Either you’ll receive a black screen in Heaven, your graphics driver will crash, or you'll start seeing little glitches on your screen that shouldn’t be there, also known as “artifacts”. These could be colored lines, blotches or black boxes that appear on your screen.

If you encounter any of these issues, your overclock is unstable. This leaves you with two options. You can either go back to your last stable core clock and skip to the next step, or you can raise your voltage and try again.

Card Voltage

Once you reach a certain point in this process, your card is going to need more voltage to be able to run at higher speeds. Increasing your voltage beyond the stock level will increase your cards power significantly, at the cost of your cards lifespan. That means that you should only proceed with this if you’re willing to make that trade.

As a standard setting, MSI Afterburner should lock the voltage on your card so you cannot raise it. In order to tweak your voltage, you’re going to have to open up MSI Afterburner's settings, and look under the general tab for the "Unlock Voltage Control" setting. Check this and click OK, and then it should bring up a new slider at the top of the Afterburner window.

Once you see that slider, you’re going to slowly increase your voltage by about 10 mV and click apply. Afterburner may slightly alter the value. Now you should run another benchmark in Heaven. If it manages to make it through the test without any artifacts or crashes, it means that your core clock is stable, and you’ll be able to try raising it again.

Now you’re going to repeat the above process. Run Heaven again, and raise the core clock after every successful and stable run. If you encounter problems, raise the voltage and retry. Keep an eye on your temperatures while you’re doing this. When you raise the voltage, your temperatures will slowly get higher. Newer cards, especially the high-end ones, are safe at around 90 degrees Celsius. Afterburner's auto fan control feature will try to keep the temperature of your card under that level. If you want to keep your card even cooler than that, you’ll be able to modify Afterburner's fan control in the settings, just look for the fan tab.

After a bit, you'll get to a certain point where you won’t be able to overclock anymore. This usually happens for one of three reasons:

  • You’ve reached the maximum voltage that you can safely provide to your card.
  • Your card has hit dangerous temperatures and your cooling system can't keep it in a safe range.
  • Your card simply can’t remain stable past a specific core clock value, regardless of the voltage you provide it. This could happen if you’re trying to overclock a card that simply doesn’t have the capacity to be overclocked.

Once you reach the point where you can no longer overclock, reduce it back down to your last stable clock speed. This is the highest possible core clock for your card. Once you've successfully finished modifying the core clock, you’ll want to repeat this entire process with the memory clock. You won’t notice as big of a performance boost with your memory speeds as you will with your core clock, but it's definitely worth raising while you’re already modifying your core clock.

Stress Test

Once you find the highest point you can overclock your card, it’s time to do some intense stress tests. Launch Heaven, and click on the Run button, and allow this to run instead of pressing the "Benchmark" button. Let this run for a couple hours, around 4 should suffice. After this, if you don't experience any artifacts or crashing, your overclock could be considered stable. Do a benchmark run and compare your score to the one you got earlier in this guide if you want to see how much your card has improved!