It's irrelevant what the bios settings are, i.e if Windows determines x amount of cores are parked, it will not use them or will attempt to un-park them during duress i.e gaming etc. Could still cause stuttering. So it's def worth un-parking whatever cores the program reports as parked. As well as making sure bios settings are ok.
I've noticed all games seem smoother to me now (COD Ghosts would stutter in weird places,def not GPU related) now it's butter. Starting to wonder if what I thought was GPU stuttering in the past was in fact parked-core syndrome lol. So much better now, night and day.