A low inertia permanent magnet motor includes a stator and rotor. The rotor includes a generally tubular and hollow rotor body coupled to the shaft of the motor by one or more spokes and/or webs. The permanent magnets of the rotor are coupled to the rotor body. In some embodiments, the low inertia permanent magnet motor may be used to power a drawworks. In some embodiments, the drawworks may be controlled by an active heave compensation controller.