Timing of power state change in a disk drive based on disk access history

摘要

A data storage device that includes a magnetic storage device and a non-magnetic nonvolatile storage device that measures a hit rate of read/write commands that result in accesses to the non-magnetic nonvolatile storage device, and adjusts a length of a time period, such as an idle time, based on the hit rate. The duration of the time period can be set each time the magnetic storage device is accessed. Upon expiration of the time period, if the magnetic storage device has not yet been accessed, the magnetic storage device is changed from a higher power consumption state to a lower power consumption state.