This can be such a complex problem. Maxing out 8 cores is rarely twice as fast as maxing out 4 cores, but it will likely make the CPU draw around twice as many watts. That makes it seem like it might be a better use of power to keep cores idle during a big compile job, but it also takes watts to drive the display and keep the backlight on.

I can't imagine this would be easy to get right, and it is probably much harder to set a good default. Even so, the background compile job taking twice as long might not be a waste of time as long as I get to play Oxygen Not Included twice as long!

Race-to-idle is sometimes a goal, yeah; if you have some performance budget (say, a 16ms time slice), and a fixed workload, does it make sense to run resources at lower power and barely meet the budget, or to run everything at max power so they can spend the remainder at idle? The answer is different for many scenarios.

Just another way too much heat can threaten your ONI run :)