Decided to boost the performance of your CPU (Central Processing Unit) without paying a dime? That’s where overclocking can help, and we already mentioned 8 reasons to overclock. If you also overclock your GPU and RAM, you’ll squeeze every drop of performance out of your computer hardware. If you are still shaky about it, stay tuned for a dedicated article on what is overclocking. Basically, it means pushing your CPU past its intended speed, and sometimes, operating voltage. How much depends you’ll push it depends on a lot of factors, some of which we mention below. Now, let’s get into how to overclock CPU.
Can I overclock my CPU?
You can’t overclock if your hardware isn’t designed for it and if the software doesn’t allow it. Here’s how to check whether your can overclock your CPU:
Here are general guidelines with CPU overclocking based on the manufacturer:
- Intel marks overclockable CPUs with a K at the end of the model. For example, Intel i9-10900K.
- AMD was known for making a majority of their CPUs overclockable, which remains true to this day. Those with an X at the end are known for achieving a better overclock than non-X models of the same name. For example, Ryzen 9 3900X.
Intel stock coolers are unsuitable for overclocking and struggle to keep the CPU on factory settings cool. Stock coolers that ship with Ryzen CPUs are much better and can be used for minimal to moderate overclocks. Anything over that, and you’ll need a third-party air or liquid CPU cooler. The higher the cooler’s rated TDP (thermal design power) over CPU’s TDP (Check CPU-Z or the manufacturer’s website), the bigger the headroom for a serious overclock.
Here’s how to recognize which motherboard supports overclocking by the name:
- A – Mini-ATX motherboards, no overclocking or (rarely) minor overclocking.
- H – No support for overclocking. Cheapest models.
- B – Supports moderate overclocking.
- Z, X – High-end motherboards to achieve the highest overclocks.
It’s important to have a high-quality PSU (Power supply unit) if you plan to overclock. The rated power output of the PSU should obviously be higher than the peak power usage of your entire system (plus a comfortable buffer). It also needs to supply power without large ripples in voltage. From our experience, the PSU should be rated for anywhere between 50 W and 200 W more than the maximum power draw of your system. To check for that, you can get a rough estimate using an online calculator. Alternatively, you can purchase a Kill-a-Watt meter and test it from the outlet.
Does automatic overclocking exist?
Certainly. Intel offers a tool called Intel Performance Maximizer. AMD has a tool called AMD Ryzen Master which can also be used for manual overclocking if you prefer its GUI and don’t like messing with BIOS.
How to manually overclock a CPU
Here are 10 steps required to overclock a CPU manually:
1. Perform a CPU stress test
To do this, you can use a host of programs such as Intel Burn Test, AIDA64, ROG RealBench, HandBrake. We use a software named Prime95 to test our hardware. Download and install a free trial version. Close all unnecessary programs and leave Prime95 running for an hour, which will push your CPU to 100% usage using a synthetic load. Here’s how to gauge your overclocking potential:
- If the CPU temperature remains low, between 50°C and 70°C, you have some headroom and can proceed immediately.
- If the temperature gets high, over 75°C, either your cooling system is insufficient, your thermal paste/thermal pad is old and crusty/worn out, or your PC case doesn’t have good airflow. Mitigate those problems before running a stress test again.
2. Measure CPU power via benchmark
Now that you know there’s potential, you need to establish baseline values. This is done through a combination of two software. We like to use these two tools:
- Cinebench R23 for benchmarking. After a CPU test, you’ll get a definite number, and can compare it to other CPUs. You can also use 3DMark.
- CPU-Z for monitoring and detailed information. We’re referring to CPU Clocks (core and boost speed), voltage, temperature, and cache. You can also use HWMonitor or HWiNFO64.
3. Reboot and access BIOS
Now that you have a benchmark number for comparison, you’re ready to begin overclocking. Restart your PC and while it’s booting, keep pressing Delete, F2, F9, or F10. The exact key for entering BIOS should be written on the screen. Follow these instructions for an alternative way to access BIOS on Windows 10:
- Open the Start tab.
- Search for ‘Startup options’ and select Change advanced startup options.
- Click on Restart now under Advanced startup.
- When it reboots, select Troubleshoot.
- Click on UEFI Firmware Settings under Advanced options.
Tip: Make sure your BIOS is updated to the latest version.
4. Find Overclocking settings
This is where we can’t give you precise information. Not only do AMD and Intel give similar or identical features different names, but so do motherboard manufacturers when they design BIOS. Furthermore, BIOS doesn’t have to be identical on a manufacturer’s low-cost H board and their Z or X high-end board. For that reason, look for an Overclocking, OC, System Tuning, or Frequency/Voltage Control section of the BIOS. You’ll recognize it by the presence of the settings mentioned below.
5. Get accustomed to CPU settings
Here are some of the basic settings required for overclocking:
Base Clock (BLCK)
The frequency at which the CPU communicates with PCIe devices and the memory. By default, the base clock is 100 MHz.
The ratio between the processor and FSB (Front-Side Bus), and also the main value you should care about. This value, multiplied by the base clock, equals CPU frequency. For example, if you set it to 40, the processor’s frequency is 40 x 100 MHz = 4000 MHz or 4 GHz.
CPU Core Ratio
Allows you to set up multiplier for CPU cores individually or one multiplier for all of them.
The amount of voltage supplied to the CPU by the motherboard.
There are typically 3 Voltage Modes:
- Manual. Set a fixed Vcore.
- Offset. Add a certain voltage number to the base Vcore regardless of the CPU frequency.
- Adaptive voltage. Only add a certain amount of voltage when the CPU is in Turbo/Boost Mode.
Load-Line Calibration (LLC)
Enabling this feature eliminates a problem called voltage droop. When a CPU doesn’t receive the voltage amount specified, LLC will compensate for the difference by providing extra voltage.
AMD Cool’n’Quiet/Intel Speedstep
Cool names for a feature that automatically increases or decreases voltage or frequency based on the current load. Enable it for energy saving.
6. Start overclocking by tweaking CPU settings
Start with increasing CPU Multiplier by one increment (+1), which raises the CPU frequency by +100 MHz. Also, change CPU Ratio from Auto to Sync Across All Cores. Save changes and exit. After a restart, one of 2 things will happen:
- You’ll boot into the operating system normally. Great news, but it doesn’t prove a whole lot. Proceed with method 7.
- You’ll get a blue screen of death. Also, your screen might freeze or remain black. This triggers a restart, and your overclocking settings will be restored to default values. There are 4 ways to proceed:
- Give up. Your CPU just isn’t capable of overclocking past default values.
- Check your temperature. There’s a chance you can overclock, but you need to get the temperature under control first.
- Play around with individual CPU core multipliers. If one of the cores is slightly less powerful than others, applying Sync Across All Cores leads to instability.
- Follow method 10 with these settings. There’s a chance your CPU was power-hungry for a little more voltage.
7. Run a CPU stress test again
Now that you booted to the desktop, it’s time to check how the CPU performs under load. Run the stress test tool for an hour or two and see if the system crashes. Keep an eye on the temperature throughout the process.
8. Repeat steps 6 and 7 until satisfied
If all seems well, continue to increase the CPU Multiplier in increments of 100 MHz. As soon as you experience any glitching, restarts, black or blue screen of death, stop. Proceed in one of the 4 ways we mentioned. If you decide you’re happy with the overclock you’ve achieved, set it to the last known stable settings and save changes.
9. Run a CPU benchmark again
It’s time to see just how much you’ve progressed. Fire up the benchmarking tool you ran before overclocking and check the current CPU power value. The difference between the two is the performance boost you’ve achieved through overclocking.
10. Reaching the best possible overclock of a CPU (Optional)
Voltage increase is the riskiest part of overclocking CPUs and isn’t recommended for first-time users. Obviously, a voltage that is too high can fry your PC parts in an instant. If you are dead-set on extracting the maximum out of your CPU safely, we recommend setting Voltage Mode to Offset and increasing it in increments of 0.03 V to 0.05 V at a time. Don’t change any other settings and continue following step 7 in-between. As soon as the instability occurs, stop and revert the voltage to the last stable offset. Start following step 8 until you reach the best CPU overclock on that motherboard.