A solid-state drive (SSD) power-mode control method that includes storing, in an active register, active mode control data used for switching the SSD from a low power mode to an active mode, storing, in a standby register, low power mode control data used for switching the SSD from the active mode to the low power mode, and controlling power supplied to the SSD in accordance with the low power mode control data or the active mode control data in response to the SSD switching (i) from the active mode to the low power mode or (ii) from the low power mode to the active mode.