Start calculating with a 3 second refresh interval for all CPU cores

Calculate the average CPU frequency over a time period.
Requires root privileges.
More information: <https://manned.org/cpufreq-aperf>.
Trick copyright: tl;dr; <https://github.com/tldr-pages/tldr>

sudo cpufreq-aperf -i {{3}}

click the source code to copy install cpufreq-aperf on any operating system with command-not-found.com