IBM System Storage DS3524 Express Dual Controller Storage System PN 1746A4D Storage type SAS HDD bays (std/max) 24/24 Hot-swap HDD Bays Yes Max Internal Storage 24TB Max Suported Storage 24TB IBM System Storage DS3524 Express DC Storage System Dual controllers 6 Gb SAS host interfaces with optional 8 Gb Fibre Channel, 10 Gb iSCSI, or 1 Gb iSCSI host interfaces 1 GB or 2 GB cache (per controller) Twenty-four 2.5-inch SAS disk drive bays Support for 192 disk drives through the attachment of EXP3524 expansion units Dual dc power supplies designed to operate from an industry-standard -48 V dc power source