Please don't get me wrong but where is the point in limiting the maximum frequency? Improving the CPU scaling management would be much better than having someone decide by himself... to give you a reasonable example, 12 cycles with scaling from 250 to 500MHz@100% do use more power than scaling from 250 to 600MHz@100% for 10 cycles so why limit it to 500MHz? I don't know what is the exact case but steps need to be reasonable and not feeling well. To run a CPU at less frequency is only a good idea to save power as long as there is no higher frequency available that uses less power for the same work.