Disk drive estimating seek time according to a seek profile and a variance group

A disk drive comprising:

• a disk comprising a plurality of tracks, wherein each track comprises a plurality of data sectors and a plurality of servo sectors;
• a head actuated radially over the disk;
• and
• control circuitry operable to:
• receive a plurality of access commands from a host, where each access command identifies a target track;
• store the access commands in a command queue;
• and
• for each access command in the command queue:
• determine a seek length corresponding to a number of tracks between a current track the head is over and the target track of the access command;
• determine a seek time in response to the seek length using a seek profile comprising a plurality of seek length segments, wherein:
• each seek length segment corresponds to a range of seek lengths;
• and
• a margin is determined for each seek length segment by measuring a throughput of the disk drive after executing a plurality of the access commands.

A method of operating a disk drive, the disk drive comprising a disk comprising a plurality of tracks, wherein each track comprises a plurality of data sectors and a plurality of servo sectors, and a head actuated radially over the disk, the method comprising:

• receiving a plurality of access commands from a host, where each access command identifies a target track;
• storing the access commands in a command queue;
• and
• for each access command in the command queue:
• determining a seek length corresponding to a number of tracks between a current track the head is over and the target track of the access command;
• determining a seek time in response to the seek length using a seek profile comprising a first plurality of seek length segments and a variance group comprising a second plurality of seek length segments, wherein:
• each seek length segment corresponds to a range of seek lengths;
• and
• the first plurality of seek length segments is different than the second plurality of seek length segments.

A method of operating a disk drive, the disk drive comprising a disk comprising a plurality of tracks, wherein each track comprises a plurality of data sectors and a plurality of servo sectors, and a head actuated radially over the disk, the method comprising:

• receiving a plurality of access commands from a host, where each access command identifies a target track;
• storing the access commands in a command queue;
• and
• for each access command in the command queue:
• determining a seek length corresponding to a number of tracks between a current track the head is over and the target track of the access command;
• determining a seek time in response to the seek length using a seek profile comprising a plurality of seek length segments, wherein:
• each seek length segment corresponds to a range of seek lengths;
• and
• a margin is determined for each seek length segment by measuring a throughput of the disk drive after executing a plurality of the access commands.