Key Features 2U chassis support max. motherboard size - ATX 12" x 10", E-ATX 12" x 13", EE-ATX 13" x 13.68". Support up to ATX 12"x13" MB with rear 2.5" HDD option installed 24 x 2.5" hot-swap SAS/SATA drive bay, optional 2 x 2.5" hot-swap drive bay 24-port 2U SAS3 12Gbps single-expander backplane, support up to 24x 2.5-inch SAS3/SATA3 HDD/SSD 1U 920W Redundant Platinum Super Quiet power supply W/PMbus 7 low-profile expansion slot(s) 3 x 8cm high-performance PWM fan(s) Optional 5 x 6cm 4pin high performance fan(s)