POWER SAVING METHOD AND APPARATUS FOR COMPUTER DISK DRIVES

摘要

A power saving method and apparatus while maintaining an operational or near-operational state for computer memory disk drives (10). A microprocessor (12) implements microcode (14) instructions to determine if a disk drive is inactive by checking if any files are currently opened or data is being transferred by the disk device. If not, the drive is considered inactive. If inactive for a period greater than a predetermined reference activity level, then the rotational velocity of the drive spindle motor (18) is reduced to its lowest operational level, or just below, without stopping the disk. In order to maintain a constant linear velocity, the spindle control slows the angular velocity of the motor resulting in a reduction of power consumed. In the case of a constant angular velocity disk drive having selectable speeds, the microprocessor controls the motor speed directly. The microprocessor, upon determining that the disk has been inactive for a predetermined threshold period, selects a constant speed that is the lowest operation speed available. The drive is returned to normal operational speed by a microprocessor "seek" command. For further savings, the motor is stopped or "spun down" when left inactive for a longer period of time.