Overclock The Raspberry PI 4 and 400

This guide shows how to overclock a Raspberry PI 4 and 400.

It is assumed that you are running the stock Raspberry PI OS and not another distribution such as Ubuntu.

1. Amend the config.txt to add overclock settings

Open a terminal window (press ctrl, alt and t) and type the following command:

sudo nano /boot/config.txt

If you would prefer to use a more visual editor, type the following command instead:

sudo mousepad /boot/config.txt

Scroll down the file until you see a line similar to the following:

arm_freq=700

There may be a # in front of it and the value may be different to 700.

To overclock your Raspberry PI amend this line to be these 2 lines:

over_voltage=6
arm_freq=2000

To save the changes using nano, press CTRL and O and press return and then press CTRL and X to exit.

To save the changes using mousepad, choose file and save from the menu.

Details of over_voltage and arm_freq can be found at https://www.raspberrypi.org/documentation/configuration/config-txt/overclocking.md.

The values for over_voltage can range from -16 to 8. This basically provides more power to the Raspberry PI. The readme page says that in order to use more than 6 for overvoltage you would need to set an additional value as follows:

force_turbo = 1

Essentially when force_turbo is 0 (the default), the overclocked settings will only be used when necessary whereas force_turbo set to 1 will use the maximum values regardless as to whether the resources are needed or not.

The arm_freq is the frequency of the ARM CPU in MHz. By default on a Raspberry PI 4 this is 1500. Raising the value to 2000 is a modest increase.

To use the new settings reboot the Raspberry PI using the following command:

sudo reboot now

2. Temperature Management

Overclocking the Raspberry PI will increase the temperature whenever the extra processing power is used. If the Raspberry PI gets too hot then the PI will default back to original settings.

The readme has a few simple commands to check temperature.

Open a terminal window and run the following command:

cat /sys/class/thermal/thermal_zone0/temp

This will return a value such as 34563. To get the result in centigrade divide the number by 1000. (IE 34.563)

Another command you can use is as follows:

vcgencmd measure_temp

This returns something like temp=36.5c

Using commands like this to monitor temperature is fine for a quick check but you don’t want to have to remember those commands every time.

There are more passive ways to monitor temperature.

If you are using the default desktop environment for the Raspberry PI right click on the panel and choose “Add / Remove Panel Items”.

Add Panel Items

Click on the “add” button.

Add CPU Temperature Monitor

Scroll down until you see “CPU Temperature Monitor” and click “Add”.

Temperature Monitor

The temperature will now be displayed in the top right corner.

Most of the time you will see that it is between 30 and 50 degrees. It will only go above this if you start doing something intense such as video editing or playing games.

3. Measuring current frequency

In step 1 I showed you how to increase the arm frequency but how can you check if it worked?

Open a terminal and type the following command:

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq

This returns a number such as 2000000. Divide the value by 1000 to get 2000 as expected.

As with the temperature you can add a panel item.

Right click on the panel and choose “add / remove panel items”. Click on “Add” and scroll down until you see “CPUFreq Front End”. Click “Add” to add this to the panel.

To see the frequency hover your mouse over the panel item. Note that this shows the current frequency being used and not the maximum frequency.

4. Use Conky to monitor settings

A far better way to monitor system settings is to use Conky.

This guide shows you how to install and use Conky to display system information on your Raspberry PI 4 and 400.

5. Troubleshooting

If after overclocking your Raspberry PI, it refuses to boot, follow these steps:

  1. Make sure you are using a suitable power supply. The official Raspberry PI power supply is recommended.
  2. Hold down the shift key whilst booting the Raspberry PI. This will boot the PI with the default configuration (IE overclocking switched off). Edit the config.txt file shown in step 1 and place a # in front of both lines. Save and reboot.