I would have to let my system run for a while to test but there is a possibility, if you system is needing more processing time than is being allowed, that it might change the settings. I do not know this to be a fact, but just a thought.
You might try a higher setting and see if it holds longer. If it is being changed, then you might check it after doing something like watching a video or playing some game, or multitasking.
Exactly how the setting is meant to work with multiple core systems, I am not sure. But most systems today do keep their processors running a little as possible. Task Manager or the Resource Monitor, may give you some information about how your processor is behaving. There have been situations were some errant process has caused the processor to run at a much higher rate than would be otherwise normal.
