Using four 500GB ADMs, the Xserve (slot-load) can be configured with 2 terabytes of internal storage. Xserve RAID may be configured with up to fourteen drives, for up to 7 terabytes of storage. Unpopulated bays ship with a blank drive carrier which can be replaced with a drive module at any time - even if the server or RAID is running - so its easy to add storage capacity as your server and storage needs grow. Xserve RAID scales in performance and capacity with the addition of ADM hard drives.