CPU frequency in Linux

See current CPU frequency

To display frequencies of all CPU cores every second:

watch -n1 lscpu --all --extended

Change CPU frequency directly

Source: Stackoverflow

Query CPU options

grep . /sys/devices/system/cpu/cpu0/cpufreq/*

Set the maximum CPU frequency

echo 4400000 | sudo tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_max_freq

Change the CPU frequency using cpufrequtils

Install cpufrequtils

sudo apt install cpufrequtils

Set the maximum CPU frequency

sudo cpufreq-set -u 4Ghz

Change the performance governor

Edit the file /etc/default/cpufrequtils

GOVERNOR="performance"

Restart the service

sudo systemctl restart cpufrequtils

Check the frequency status of each core

cpufreq-info