The computer is smart enough to accel to max when needed. You'll be fine. I forget what you have to do to make it run at max when plugged (since it's not in front of me), but most old systems have a default to run at max when plugged anyways. Sometimes its doesnt register correctly also that it's running at max. Even if it was at max, you probably wouldnt see any difference at all, because it's usually switches lower when its idling. Why switch to max process when idling? It'll only increase battery usage, wear n tear, heat, and sometimes fan noise.