For greater performance from your CPU or GPU (as well as a more responsive computer), overclocking is an option. It’ll make your CPU run faster than the manufacturer originally intended which means that you’ll enjoy performance equal to higher priced models – without the expense.
As you’ll no doubt be aware, overclocking does present some disadvantages. Keep the following in mind:
- CPU damage. The CPU produces additional heat when it’s overclocked and if there is insufficient cooling, it may become physically damaged. Some users experience blue-screen, system errors and restarts. If this happens, you’ll need to reset the BIOS – check your motherboard’s manual for full instructions.
- Void warranty. More importantly, the CPU’s warranty becomes void if it’s overclocked which means you won’t be covered if it becomes damaged. Remember that overclocking is done entirely at your own risk.
- Hardware damage. If the CPU is left in an overheated or undercooled state for a prolonged length of time, it can cause ongoing damage to your PC’s hardware and you may find you need to buy replacement parts to remedy the issues caused.
That said, if you know what you’re doing and you take your time, overclocking is not as complex as you might expect and it could help to significantly improve the performance of your PC.
Can All CPUs Be Overclocked?
In short, no. The majority of CPUs and motherboards’ multipliers are locked and therefore unable to support overclocking.
If you’re interested in overclocking, you’ll need to make sure you have the right type of CPU:
- Intel CPUs – look for products with a ‘k’ in the name. Intel has just released its sixth-generation unlocked CPUs which are ideal for overclocking.
- AMD CPUs – look for a Black Edition chip, such as the AMD FX8-8350 Black Edition.
You’ll also need a motherboard that supports overclocking:
- Intel – all ‘z’ designated motherboards, e.g. Intel Z170.
- AMD – the majority of AMD motherboards support overclocking. Find AMD chipsets here.
Before You Overclock…
You’ll need to consider additional cooling. As overclocking causes your CPU to produce additional heat, you’ll need to prevent your system from becoming too hot – otherwise it’ll result in physical damage.
- Ensure there is good airflow throughout your PC’s case. The more efficiently you can remove heat from the CPU, the more stable the overclock will be.
- Heat sinks work well. Invest in an additional heat sink or a more powerful CPU fan to help remove the heat faster.
- Thermal grease is critical. Even the best heat sinks will not properly have heat transferred into them from the CPU without a layer of thermal grease. The thinner the coating the better; it creates an ideal interface between CPU and heat sink to maximise heat dissipation. Wear gloves to apply and do not get it in your eyes! Follow this step-by-step guide:
- Water cooling works better than air cooling. Any heat inside your PC’s case will be absorbed by the water and then pumped out and expelled into the air. If you prefer air cooling, the Noctua NH-D15 is well-known for its quiet cooling performance.
How To Overclock
You’re almost ready to start the overclocking process. There are three methods to choose from:
- Use the motherboard’s automatic overclocking tools. Consult your motherboard’s manual for further details – this method is useful for those who are new to overclocking but doesn’t always give the best results in terms of performance. If you’ve automatically overclocked before, you’ll notice it tends to increase the voltage too much too soon, causing the temperature to rocket and your PC to become unstable.
- Use your operating system’s software to manually overclock. This is the only way to overclock a GPU (more on this later).
- Manually overclock in your motherboard’s BIOS. The method of focus below. It’s more stable and you’ll achieve significantly improved performance by using the BIOS to overclock.
Firstly, back up any important data, make sure you’re running the latest version of your motherboard’s BIOS and install the following free software. You’ll use this to test your system is stable during the overclock process:
- CPU-Z: uses real-time information to monitor your processor’s clock speed and to check the amount of voltage being applied.
- Prime95: tests your system’s stability over a prolonged period.
- Real Temp: monitors the temperature of your CPU and allows you to ensure it doesn’t exceed 70 degrees (indicating the CPU is at full capacity).
Overclocking In The BIOS – Step By Step
Once you’ve done all of the above, you’re ready to start overclocking:
- Open the BIOS. Hold down the ‘delete’ key when you start your computer.
- Open the ‘overclocking’ menu. May be labelled as ‘frequency/ voltage control’.
- Reduce memory bus speed. This will prevent any errors being caused by the memory. To reduce the speed, look for the memory frequency options – press Ctrl+Alt+F1.
- Increase your processor’s base speed by 10%. This may be labelled as base clock – a low speed which is multiplied to gauge the total speed capability. For example, a 100MHz base clock with a multiplier of 16 will give a total clock speed of 1.6GHz. Increasing this number by 10 per cent would up the base clock to 110MHz, giving a clock speed of 1.76GHz.
- Perform a stress test. It’s time to restart your computer and boot into the OS. Check the stability of your PC and keep Real Temp open to monitor the temperature.
- Keep increasing the base clock. Increase it by a small amount each time (5-10MHz) until the system becomes unstable. Don’t forget to run a stress test after every adjustment.
- Adjust the multiplier on the motherboard for improved performance. Look for ‘CPU Ratio’ and change the settings from ‘Auto’ to ‘Sync Across All Cores’. Increase the multiplier number by one. Referring back to our example where the multiplier was 16 and the clock speed was 1.6GHZ, adding one to the multiplier gives a total speed of 1.7GHz.
- Run the stress test again for every multiplier increase.
- Check the temperature. It’s possible that you’ll reach the temperature limit before the system becomes unstable. If so, this is the limit of overclocking for your PC. As a general rule, CPU temperatures should not exceed 70 degrees.
- Return the multiplier to its last stable point. Providing the temperature is still within the safe limit, you can now start to adjust the voltage levels for further performance increases. This is the most risky part of the process so take it slowly.
- Increase the core voltage of the CPU. Raise the voltage by 0.025 each time. Don’t go higher than this as it’s easy for the voltage to become too high very quickly, damaging your components.
- Run a stress test after the first voltage increase. If the system is stable, check the temperature is still within the safe limit. If it’s still unstable, reduce the base clock speed or the multiplier and check again.
- Go back to the multiplier or base clock section. Once you’ve returned your unstable system to a stable state through increasing the voltage, you can start to increase either the multiplier or base clock speed again. Don’t forget to run a stress test after every increase until the system becomes unstable.
- Increased voltage has the greatest effect on temperature so try to find the highest base clock and multiplier settings to improve performance, leaving the voltage as low as possible. You’ll need to try different variations until you find the best settings for your CPU.
- Repeat the process until you reach the maximum voltage or temperature. This signifies the limit of your CPU and motherboard. Remember:
- Voltage should not be increased by more than 0.4 above the original level.
- If the temperature limit is reached before the voltage limit, improving your PC’s cooling system may enable you to make further increases.
- Reduce the multiplier or the base clock to its last safe setting. You should notice that the CPU speed is larger than it was originally.
- Increase the memory speed. Bring the memory speed back to its original level slowly, running a stress test each time.
- Run a longer stress test. It’s time to use Prime95. Open the software and allow the test to run for a minimum of 12 hours to ensure your system remains stable over an extended time period. If it becomes unstable at any point, readjust the voltage, multiplier and clock speed until you find the optimum levels.
- Perform a real-life test. Choose one of your high-spec games and see whether or not your system remains stable while it’s running. You should notice an improved performance.
What About GPUs?
All GPUs are overclockable, although doing so will shorten its lifespan unless you have a decent cooling unit. Some of the best titles to test overclocking with include Battlefield 4, Crysis 3 and Call Of Duty Advanced Warfare. Remember, overclocking can only be achieved by using the software tools (provided by the GPU manufacturer).
AMD and Nvidia provide overclocking support with their drivers:
- For AMD, head to Catalyst Control Center > Performance
- For Nvidia, install System Tools utility to unlock the tool
Simply adjust the fan speed, clock speed and memory speed sliders and use your highest spec game to test the results. As the voltage is not adjusted with built-in overclocking tools, there’s no need to be as cautious with the adjustments – choose the overclock settings that work best for your needs.
Download GPU-Z to monitor the temperature of your GPU as you make each increase. As a general rule, do not let your GPU exceed 85 degrees.
All overclocking should be approached with some caution if you’re worried about causing long-term damage to your system. Remember to consider upgrading all cooling systems prior to overclocking – if possible, with water cooling – and make sure your CPU case has all the fans it can support, running. Extra cooling will help you to achieve greater levels of overclocking safely.
What’s your experience with overclocking? Share your stories with us today!