Abstract: A unique system and method for ordering commands to reduce disc access latency while giving preference to pending commands. The method and system involves giving preference to pending commands in a set of priority queues. The method and system involve identifying a pending command and processing other non-pending commands in route to the pending command if performance will not be penalized in doing so. The method and system include a list of command node references referring to a list of sorted command nodes that are to be scheduled for processing.

Abstract: Apparatus and method for transferring data between a disc drive data storage device and a host device. Access commands are provided by the host device to the data storage device to read and write data. Write caching is employed so that the write data are temporarily stored in a buffer. A phase time (access time) is determined for each pending access command, and the access commands are executed in relation to the identified phase times. However, when the total amount of accumulated write data in the buffer exceeds a first threshold, a thread of write commands having an intermediary phase time less than a selected duration is selected and written in lieu of other pending access commands. When the total amount of accumulated write data exceeds a second threshold, as many write commands are serviced as possible during a preselected purge time.

Abstract: Apparatus and method for transferring data between a disc drive data storage device and a host device. Access commands are provided by the host device to the data storage device to read and write data. Write caching is employed so that the write data are temporarily stored in a buffer. A phase time (access time) is determined for each pending access command, and the access commands are executed in relation to the identified phase times. However, when the total amount of accumulated write data in the buffer exceeds a first threshold, a thread of write commands having an intermediary phase time less than a selected duration is selected and written in lieu of other pending access commands. When the total amount of accumulated write data exceeds a second threshold, as many write commands are serviced as possible during a preselected purge time.

Abstract: A unique system and method for ordering commands to reduce disc access latency while giving preference to pending commands. The method and system involves giving preference to pending commands in a set of priority queues. The method and system involve identifying a pending command and processing other non-pending commands in route to the pending command if performance will not be penalized in doing so. The method and system include a list of command node references referring to a list of sorted command nodes that are to be scheduled for processing.