sentences:  Staggered spin-up typically starts one drive at a time, either waiting for the drive to signal it is ready or allowing a predefined period of time to pass before starting the next drive.If the power supply is able to supply sufficient current to start multiple drives at a time, that, too, is common.Staggered Spin-up (SSU) and Power-Up In Standby (PUIS) are different features that can help control spin-up of multiple drives within a computer system or a disk subsystem.