Velocity at which the disk media spins within a hard disk, measured in rpm (revolutions per minute). By the late 1990s EIDE hard disks generally features a 5,400rpm or 7,200 mechanism, while SCSI drives were usually either 7,200rpm or 10,000rpm.

The rate at which the spindle is turning. Expressed in RPM. Must always be set according to workpiece diameter.

See RPM.