cpupower-gui VS plasma-pstate

I use cpupower-gui for this, and installing the .deb on their releases page works flawlessly. In my experience, it does a pretty good job at improving battery life, even on modern systems.

I was looking into using envycontrol to disable the dGPU in linux, and maybe ryzen controller or cpu-power to limit cpu power usage.

For power management, you could use something like cpupower-gui to underclock the CPU whenever you need to conserve battery.

There's https://github.com/vagnum08/cpupower-gui but its GTK based

I use gnome so I have no clue what the KDE slider does, sorry! But you should check out cpupower-gui

You can also use cpupower-gui to park cores, although Phawx mentioned he used some other tool. In this tool, you just need to uncheck the cpu you need to turn off.

Also I would recommend using cpupower-gui if your frequencies are too high. This tool lets you do frequency scaling and lets you select a governor in a gui.

github for cpupower-gui

Well, I just tried it on my Gentoo system, the UI seemed a bit bugged out (couldn't click the governor combo box). Perhaps I didn't build it correctly. Then I tried a more recent fork (https://github.com/ismaelbonato/plasma-pstate/tree/dev) and that one worked a bit better.