Abstract: Tilt between a head stack and its associated disk stack in a hard disk drive (HDD) is measured by determining the deviation of a target head from its expected position (based on the position of the current head) each time electrical contact is switched from the current head to a target head. A running average tilt value is stored and used to modify the logical seek distance used in a Rotational Position Optimization (RPO) algorithm to better order I/O requests in a queue. Also, the running average tilt value can be used by the servo to pre-position the target head before electrical contact is made with the target head, to improve speed of operation.

Abstract: Tilt between a head stack and its associated disk stack in a hard disk drive (HDD) is measured by determining the deviation of a target head from its expected position (based on the position of the current head) each time electrical contact is switched from the current head to a target head. A running average tilt value is stored and used to modify the logical seek distance used in a Rotational Position Optimization (RPO) algorithm to better order I/O requests in a queue. Also, the running average tilt value can be used by the servo to pre-position the target head before electrical contact is made with the target head, to improve speed of operation.

Abstract: Tilt between a head stack and its associated disk stack in a hard disk drive (HDD) is measured by determining the deviation of a target head from its expected position (based on the position of the current head) each time electrical contact is switched from the current head to a target head. A running average tilt value is stored and used to modify the logical seek distance used in a Rotational Position Optimization (RPO) algorithm to better order I/O requests in a queue. Also, the running average tilt value can be used by the servo to pre-position the target head before electrical contact is made with the target head, to improve speed of operation.

Abstract: An attachment structure and method for a disk drive apparatus for making the coupling resonance frequency of a hard disk drive the same whether one disk is loaded or a plurality of disks are loaded based upon parameters obtained from a simulation model. The modeling of a coupling vibration for one disk and for two disks is performed using a coupling vibration model of a linear two degree-of-freedom system. The component parts of a spindle motor providing a spring constant Kp are adjusted so that the resonance frequency determined by coupling that of a spindle motor with that of the disk(s) is made much the same whether one disk or two disks are loaded. This adjustment enables stable track following to be secured without the need for adding dummy disks and other parts.