A direct access storage device and a method of operation thereof where the output of the circuit which controls energy to the position actuator for the head may be changed at times between receipt of sequential position error signals from the medium. Instead of waiting for the next position error signal, a computation is done based on at least the current position and the desired position of the head as to when the head velocity will be equal to a desired velocity. The optimum time to switch is estimated, the energy required to achieve a predetermined velocity and a predetermined offset with respect to the desired position are computed, and operation is conducted accordingly. The amount of energy may again be changed at a time subsequent to the estimated time. The predetermined velocity and the predetermined offset may be zero or may have values other than zero in accordance with the requirements of the track following controller.