Various illustrative aspects are directed to a data storage device, method, and one or more processing devices that are configured to: during a read operation, open a servo gate in the selected head in order to read the first servo bursts, the sync mark, and the second servo bursts in one of the servo sectors; and determine a position error signal for the selected head based on reading the first servo bursts and the second servo bursts.

According to the embodiment, a controller of a magnetic disk device executes, for each of unexecuted commands, a first operation to estimate a seek time for executing a corresponding command. The first operation includes acquiring a first force constant of the motor and a second force constant of the motor, and estimating a seek time based on the first and second force constants and a seek distance. The first force constant is determined when the magnetic head is at a start position of a seek operation. The second force constant is determined when the magnetic head is at an end position of the seek operation. The controller determines a command to be executed first out of the unexecuted commands based on the estimated value of the seek time obtained by the first operation for each of the unexecuted commands.