Embodiments in accordance with the present invention allow a magnetic disk
drive to achieve noise reduction and low power consumption through
rotation at a low speed and a high transfer rate through rotation at a
high speed while allowing reliability to be maintained and achieving an
improved recording density. An embodiment of a magnetic disk drive in
accordance with the present invention includes, a magnetic disk medium
driven at a plurality of rotational speeds, a magnetic head for recording
and reproducing data in and from the magnetic disk medium, a heater for
controlling a flying height of the magnetic head, and a control unit for
controlling the current to the heater, and in that the control unit
controls the current to the heater. The control unit controls the current
to the heater according to the plurality of rotational speeds.