Raspberry Pi 4 Overclocked!

We’ve got a new Raspberry Pi model on the market and now it’s time to play with it. Let’s see the capabilities of the Raspberry Pi 4B overclocked.

I’ve also overclocked the Raspberry Pi 3B+ model, please take a look at the post.

We just have to edit the file with the following line on a new terminal window,

sudo nano /boot/config.txt

and near the bottom of the file we’ll add the following lines:

gpu_freq=500

sdram_freq=550

arm_freq=1550

over_voltage=8

force_turbo=1

Explaining these lines

• gpu_freq sets core_freq, h264_freq, isp_freq, and v3d_freq together. On Pi 3/Pi Zero /Pi Zero W core_freq defaults to 400 and h264_freq, isp_freqand v3d_freqdefault to 300; on the Pi 4B the core_freq, h264_freq, isp_freq, and v3d_freq default value is set to 500.
• core_freq is the frequency of the GPU processor core in MHz. In other words, It has an impact on CPU performance because it drives the L2 cache and memory bus. Default value is 400 for the Pi 3 and Pi Zero and Pi Zero W. Note that the L2 cache benefits only the Pi Zero/Pi Zero W and Pi 1, but there is a small benefit for SDRAM on the Pi 2/Pi 3, and there is no effect on the SDRAM on the Pi 4B.
•  h264_freq adjusts the frequency of the hardware video block in MHz. Individual override of the gpu_freq setting, isp_freq sets the frequency of the image sensor pipeline block in MHz. Individual override of the gpu_freq setting, and v3d_freq, frequency of the 3D block in MHz, and independent override of the gpu_freq setting.
• sdram_freq modifies the frequency of the SDRAM in MHz. The default value is 500 on the Pi3B+, and 3200 on the Pi 4B.
• over_voltage regulates the CPU/GPU core voltage. [-16,8] equates to [0.8V,1.4V] with 0.025V steps. In other words, specifying -16 will give 0.8V as the GPU/core voltage, and specifying 8 will give 1.4V. Values above 6 are only allowed when force_turbo is specified: this sets the warranty bit if over_voltage_* is also set.
• arm_freq sets the frequency of the ARM CPU in MHz. Default value is1400 for the Pi 3B+ and 1500 for the Pi 4B.
• force_turbo param forces turbo mode frequencies even when the ARM cores are not busy. Switch this on may set the warranty bit if over_voltage_* is also configured.

  You can get more info about those settings at Raspberry Pi Docs.

Making some tests

Changing those parameters, we’ve got our Raspberry Pi 4B overclock ready! Above all that system changes, I’ve tried to do some memory and system benchmarks, to set an appropriated values and try avoid data loss. Pick the right settings.

Some great settings for Raspberry Pi 4B overclock are these highlighted in yellow.

Tests have been run with the sysbench utility.

sysbench --test=cpu --cpu-max-prime=20000 --num-threads=4 run

[Default values]
gpu_mem=512
gpu_freq=500
sdram_freq=3200
arm_freq=1500

[Overclocked]
gpu_mem=512
gpu_freq=600
sdram_freq=3200
arm_freq=1600
over_voltage=8

[Overclocked]
gpu_mem=512
gpu_freq=600
sdram_freq=3200
arm_freq=1650
over_voltage=8

[Overclocked]
gpu_mem=512
gpu_freq=600
sdram_freq=3200
arm_freq=1700
over_voltage=8

[Overclocked]
gpu_mem=512
gpu_freq=600
sdram_freq=3200
arm_freq=1750
over_voltage=8