3U, 13.68" x 13" E-ATX and ATX, 16 x 3.5" hot-swap drive bay, optional 2 x 2.5" hot-swap drive bay, 16-port 3U SAS3 12Gbps dual-expander backplane, support up to 16x 3.5-inch SAS3/SATA3 HDD/SSD (secondary expander port only connects to dual-port SAS devices, single-port SATA will not have this redundancy feature), 1U 800/1000W Redundant Titanium Single Output Power Supply W/PMbus, 7 full-height & full-length expansion slot(s), 3 x 8cm hot-swap redundant PWM cooling fan(s), 2 x 8cm hot-swap exhau