How to overclock your CPU: fine-tuning for your processor

The CPU (Central Processing Unit) is the part of a computer that processes data and communicates commands. For this reason, the CPU plays a crucial role when it comes to how quickly and reliably a PC operates. In addition to the computer’s current usage, it is the CPU’s performance capacity that has the biggest impact on the speed with which the respective programs and processes are able to run.

The most important unit for measuring a processor’s performance capacity is clock speed. This is specified in hertz (Hz) and provides information on the speed with which data and commands are being processed. The higher the clock speed, the quicker the computer can complete tasks. Programs that demand a lot of processing power also perform better with higher clock speed.

If the CPU is somewhat outdated, it may be the case that the clock speed determined by the manufacturer for newly-developed high-performance programs is no longer adequate. This will become noticeable in the form of long delays as well as an exceptionally high CPU usage, which can cause programs to temporarily freeze, and in the worst-case scenario can even lead to a system crash. However, there is an option to increase performance capacity and accelerate data processing: overclocking the CPU.

In addition to the data transfer rate, the clock speed is one of the most crucial units for measuring how fast a CPU completes the computing process needed to process data. This clock speed is usually determined by the manufacturer and indicated in the CPU’s product specification. However, in most cases, the value does not represent the processor’s maximum performance capacity. Rather, the indicated speed meets the demands of most users, while at the same time enabling optimal energy-efficiency and the best lifespan for the CPU.

But what happens if the CPU’s clock speed is inadequate for your computing needs? This can happen, for example, if you use high-performance programs and raw data formats for editing photos and videos, or if you are a passionate gamer. Instead of considering a replacement of your CPU, you can manually increase the CPU’s clock speed in order to improve processing power. This is called overclocking the processor. The overclocking designation came about because the clock speed that was originally indicated is deliberately exceeded.

It’s also worth mentioning that overlocking is not only possible with the CPU, but with all PC components that operate with a periodical clock signal. That is to say, for example, a video card or RAM. If you operate all hardware components in-sync with a higher clock speed, you can increase your PC’s system performance considerably.

Before you get down to action, you should be aware that your PC operates as a complete unit. If you change specific parameters, this also has an effect on other components. The most important thing is to provide sufficient cooling because when you overclock your PC, it will inevitably produce more heat. To protect from overheating, the system automatically curbs its performance (in other words, the clock speed) as soon as the sensors report temperatures above the established threshold. This is exactly what you don’t want to happen when you overclock the CPU. Moderate overclocking (up to two speed grades higher than specifications) should be safe, but if you plan on doing heavier overclocking, you should set up a good cooling system. You can do this by either increasing the speed of the built-in cooler or by retrofitting a high-performance external cooling system (e.g. coolers using water or nitrogen).

Another safety hazard is increased voltage. Make sure that the power supply can withstand this value or limit increasing the voltage to the extent that it is permitted in the technical specifications. In general, we recommend that the performance increase should only exceed the clock speed increase. Although it’s true that raising the voltage does produce much higher performance, it demands so much from the individual components that the life span in most cases decreases considerably.

If the technical specifications of your hardware and software meet the requirements for a higher clock rate, then you can get started by installing the necessary monitoring and testing tools, and under careful observation, incrementally change specific parameters for your CPU.

First, you should install tools with which you can monitor the CPU temperature and use. They allow you to check what effects the clock speed increase had and also whether the system remains stable under added stress. We recommend CPU-Z and HwiNFO, which are both available as freeware. With these tools, you can not only monitor the clock speed, temperature, and voltage in real-time, but also view graphs of the activity and performance data curves.

You’ll find the settings and options for overclocking your processor in your computer’s BIOS (Basic Input/Output System) or in the UEFI (Unified Extensible Firmware Interface) in newer PCs. In most cases, you can access these when turning on your computer by pressing the “delete” key or one of the function keys. With regard to mainboards, most of them include tools via which you can perform the setting changes for overclocking. However, the BIOS/UEFI is more suitable for making adjustments, as you can bypass possible motherboard manufacturer restrictions from there.

For overclocking the processor, the front-side bus, multiplier, and core voltage values are important. You may need to change into your BIOS/UEFi’s expert mode beforehand in order to be able to see and change these values.

Record the standard settings as well as the values for every specific overclocking step so that you can undo the changes at any time if the system becomes unstable. The CPU’s clock speed consists of the front-side bus and a multiplier. Make sure you record the defaults for these values.

Most processers have a standard activated turbo or booster function that automatically increases the clock speed when there’s higher usage. You should deactivate this before changing settings so that you don’t distort the results during later test runs.

Increasing the multiplier promises the most effective performance increase. You should proceed with this in the smallest possible steps (either 0.5 or 1), then restart the PC and check the clock speed as well as the temperature and voltage values. If your system doesn’t indicate any issues during the subsequent stress test, you can increase the multiplier value again.

With many manufacturers, the multiplier cannot be changed, or can only have minimal changes made to it. In this case, you must fine-tune the front-side bus in order to overclock the CPU. Here, small steps and continuous monitoring are the surest way to protect the system from overloading.

In most modern motherboards, the CPU’s clock speed and voltage are coupled to each other. This means, that as soon as you make changes to the multiplier, the voltage automatically increases to the optimal value. If you still want to manually increase the value, you should proceed with extreme caution. A high-performance cooling system and careful monitoring of the temperature are essential to prevent irreparable damage to your PC.

After every change of a specific parameter, your PC must be checked to see if it still runs stably. It’s not enough to just restart the system and open a few programs and websites. Because you are overclocking your CPU in order to improve processing power, you must also stress test the stability of the PC with the new settings under a heavy load. Otherwise, you could find yourself in a situation where everything looks good at first glance, but your system will not withstand the constant strain caused by games or video editing.

In order to simulate the maximum load, there are so-called stress tests which push the CPU (and other components) to the limit. You should carefully monitor the CPU temperature and clock speed while the program runs, and immediately stop the test if the values rise to a critical limit. At this point, adjust the changed parameters downwards again until you have optimized your system so that it runs stably with a heavy load on a sustainable basis.