How do you optimize Linux to use as little power a possible when idling?
Ideally, programs and kernel threads should use not even one single CPU cycle until they are actually manually activated.

>>105998809 (OP)
download a kernel, compile it, configure it, add your stuff on top of it, and measure power from the wall?

some of this stuff is controlled by the bios though

>>105998809 (OP)
Powertop
You can also lower power usage in the BIOS by a lot