Operating System :Windows 10 Home & Pro MAR, Ubuntu Linux, Free DOS Chipset :Intel X58 Express Processors :Dual/Quad/Six Core Intel Xeon 3500/3600 Series Processors Memory Support :4-DIMM slots/ 6-DIMM slots (depending on base unit model) for PC3-10600 DDR3-1333 ECC memory Hard Drive :250GB to 2TB SATA 3.0-Gb/s, 300GB to 600GB SAS, 128GB to 256GB SSD Drives Removable Media :16X DVD-ROM SATA Drive, 16X DVD+/-RW SuperMulti SATA Drive, Blu-ray Writer Expansion Bays :External: Three (3) 5.25-inch, Internal: Two (2) 3.5-inch Expansion Slots :2 PCIe x16 Gen2 Slots, 1 PCIe x4 Gen2, 1 PCIe x4 Gen1, 2 PCI Slots Graphics :N/A Audio :Integrated Intel/Realtek HD ALC262 Audio Communications :Integrated Broadcom 5764 PCIe LOM Controller I/O Ports :Front: Two (2) USB 2.0, Headphone/Mic, Rear: Six (6) USB 2.0, 2 PS2, Serial, Audio I/O Input Devices :Standard Keyboard (USB or PS/2), Mouse (USB or PS/2) Power :475W, 85% efficient Power Supply Dimensions :45.53 x 45 x 16.79 cm Weight :15.1 kg