see the answers [here](https://askubuntu.com/questions/1322492/how-to-set-as-default-performance-mode-on-ubuntu-20-04-instead-of-powersave). You can either create a sercvice as in one of the answers or specify the desired governor on the grub command line as in method 2 of my answer.
– Doug SmythiesDec 29 '22 at 21:15