Patent ID: 7535666

Claim:
A disk-type storage medium driving apparatus that can switch rotation speed of a disk-type storage medium to drive the disk-type storage medium, comprising: at least one communication interface unit, which performs data transfer to and from peripheral devices; a control unit that judges necessity of switching rotation speed of the disk-type storage medium when there occurs a data transfer request through any of the at-least-one communication interface unit; an interface management table in which a data transfer rate index value is recorded for each communication interface unit, and a media management table in which a data transfer rate index value is recorded for each rotation speed that can be switched; the control unit acquires a data transfer rate index value that is considered necessary on the basis of the data transfer rate index value at a rotation speed before the data transfer request and the data transfer rate index value of the interface unit relating to the data transfer request, and determines a rotation speed that satisfies the acquired data transfer rate index value, to judge necessity of switching the rotation speed; and wherein the control unit adds the data transfer rate index value at the rotation speed before the data transfer request to the data transfer rate index value of the interface unit relating to the data transfer request, and takes a sum obtained or the sum multiplied by a predetermined value, as the data transfer rate index value that is considered necessary.