Hybrid drive migrating data from disk to non-volatile semiconductor memory based on accumulated access time

A hybrid drive is disclosed comprising a head actuated over a disk comprising a plurality of data tracks, and a non-volatile semiconductor memory (NVSM). An access command is received from a host, the access command identifying at least one target logical block address (LBA). When the target LBA is mapped to a target data track on the disk, the head is positioned over the target data track and an accumulated access time is updated for the target LBA. The accumulated access time is compared to a first threshold, and the target LBA is migrated to the NVSM in response to the comparison.