For the GE CF6 engines, full forward throttle lever = full thurst. In the new CF6-80 with electronic engine control, that is limited by the EEC for current conditions. For the old CF6-50 with mehcanical fuel control, full forward may give an overspeed or overtemp or overthrust.
In either case, using the autothrottle with a fixed derate will move the throttles to a position aft of full forward. More thrust is available by manually pushing the levers to the stops.