The Raspberry Pi 4 comes equipped with an ARM Cortex-A72 CPU operating at a maximum clock speed of 1.5 GHz. This means that the processor updates at an impressive (for its size) 1 and a half billion times per second! For the sake of curiosity, let’s see what happens when we supply it with more power and change the maximum clock speed.
Warning! Following the instructions within this article may lead to data loss and permanent damage of your Raspberry Pi 4.
The Raspberry Pi 4 typically idles at around 600 MHz and jumps to the maximum default speed of 1.5 GHz as needed.
Overclocking your Raspberry Pi pushes more power to and sets a higher maximum speed for your CPU and other components.
You can adjust the CPU (central processing unit) and GPU (graphics processing unit) clock settings within config.txt located within the main “boot” directory.
Begin by ensuring that you are running the latest version of your Raspberry Pi OS and software. Tweaks to your Raspberry Pi’s performance are being published all the time and you may achieve even faster speeds with the latest software release. To ensure you are using the latest software follow my tutorial on how to update Raspberry Pi 4.
After updating and rebooting your Raspberry Pi lets move onto the dangerous and fun part.
To set the overclock settings on your Raspberry Pi 4 open a Terminal window and enter the following command.
sudo nano /boot/config.txt
This will open the nano file editor tool with the config.txt file loaded. Scroll down to the following comment section.
#uncomment to overclock the arm. 700 MHz is the default.
Below that line, enter a new line with the following value:
Then uncomment the next line (#arm_freq=800) by removing the # symbol from the beginning and set the arm_freq value from 800 to 1750 as seen below.
You should now have the following lines:
#uncomment to overclock the arm. 700 MHz is the default.
Feeling lucky? Perhaps you will want to also give overclocking the GPU a go. But I personally advise going slow and ensuring that you have a stable Raspberry Pi by testing it thoroughly before attempting to use it in any type of production environment.
Otherwise, simply save the config.txt file by pressing CTRL + S then exit the Nano editor by pressing CTRL + X.
While still within the nano editor for the config.txt file, you can also add the following variable:
The default value is 500, and I’ve been able to set it as high as 750 without too many issues. Any higher and my Pi’s failed to boot or slowed down due to overheating and under voltage issues. I’ve read that it is unlikely to maintain this speed for the long run. Which is why I don’t advise change this value.
The gpu_freq oversees a range of settings:
The core_freq setting adjusts the frequency of the GPU processor. It influences CPU performance because it drives the L2 cache and memory bus. Again, I don’t advise messing around with these values.
Okay, what have we done? First, we set the over_voltage command which adjusts the core CPU/GPU voltage. This accepts values ranging between -16 and 8. The default value is 0 and we set it to 2. Next we set the CPU operating frequency (arm_freq) from a maximum of 1.5 GHz to 1.75 GHz.
Finding the highest stable settings that your Raspberry Pi 4 will handle involves bumping up the voltage and CPU operating frequency (arm_freq) until it crashes. If this happens, there is a good chance of corrupting your microSD card and any other connected data storage devices. Only experiment with a spare microSD card, clean Raspberry Pi OS installation and ensure that no important data is at risk!
A faster CPU speed demands a higher voltage and, if Raspberry Pi doesn’t get enough power, you will see a small lightning bolt appearing in the top right of the window. Otherwise, the CPU clock speed may be reduced to the default speed of 700 MHz. To obtain reliable performance it is essential to keep the power supply voltage above 4.8 V.
Note that the voltage from some USB chargers/power supplies can fall as low as 4.2 V. This is because they are usually designed to charge a 3.7 V LiPo battery, not to supply 5 V to a computer. To monitor Raspberry Pi’s voltage, you will need to use a multimeter to measure between the VCC (5 V) and GND pins on the GPIO.
With the new parameters in place to provide the CPU with a bit more power and a new upper maximum arm_freq of 1.75 GHz we are ready to reboot so the settings take effect.
To reboot your Raspberry Pi enter the following command in your Terminal window.
Assuming that you have correctly set the voltage and clock variable in the prior step and, more importantly, that your Raspberry Pi booted we can move onto checking if we officially overclocked our Raspberry Pi.
To do this, lets check the operating clock speeds by opening up a Terminal window and entering the following command.
watch -n 1 vcgencmd measure_clock arm
The watch command will continuously return the vcgencmd measure_clock arm value so we can monitor the clock speed in (near) real time. As you use your Raspberry Pi, the requested speed should boost to its new upper level of 1750000000 or 1.75 GHz.
Congratulations, you’ve officially overclocked your Raspberry Pi 4.
Note, if your Raspberry Pi’s clock speed is registering lower, it might be throttled due to low voltage or over temperature issues. See troubleshooting overclocking issues below.
Most overclocking issues result in failure to boot. If this happens simply press and hold down SHIFT during the next boot. This will override any overclock settings and allow you to boot so that you can change the settings within your /boot/config.txt file.
Alternatively, you can (with the power off) remove the microSD card from your Raspberry Pi and insert it into another computer. You will be able to access the config.txt under the boot directory so that you can edit the settings within.
Overclocking Issues Overview
- If your Raspberry Pi gets too hot, the unit will slow down in an effort to prevent damaging its components.
- If the voltage is too low, you will need to purchase a new or more powerful Raspberry Pi power supply.
- If the Raspberry Pi failed to boot, you will need to restore or edit your original /boot/config.txt file.
I welcome your thoughts, questions or suggestions on my article on how to overclock a Raspberry Pi 4.
Let me know if you found any errors within my article or if I may further assist you by answering any additional questions you may have.