Operating System :Windows 7 Home & Pro. MAR, Windows 10 Home & Pro MAR, Ubuntu Linux, Free DOS Chipset :Intel® C216 chipset Processors :Intel® Xeon? processor E3 v2 family, 3rd gen Intel® Core™ processors, Dual-Core Intel® Pentium® processors Memory Support :4 DIMM slots, supporting up to 32GB ECC/non-ECC, DDR3 1600 MT/s Hard Drive :250GB to 2TB SATA 3.0-Gb/s, 128GB to 512GB 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: Three (3) 3.5-inch Expansion Slots :1 PCIe Gen3 x16 slot, 1 PCIe Gen2 x4 slot (x16), 1 PCIe Gen2 x4 slot (x8), 2 PCIe Gen 2 x1 slot, 2 PCI slots Graphics :Intel Integrated Graphics Media Accelerator HD Audio :Integrated Realtek HD ALC221 Audio Communications :Integrated Intel 82579LM PCIe GbE Controller I/O Ports :Front: 1 USB 2.0, 2 USB 3.0, Headphone/Mic, Rear: 4 USB 2.0, 2 USB 3.0, 2 PS2, Serial, Audio I/O, DVI-I, DP Input Devices :Standard Keyboard (USB or PS/2) Mouse (USB or PS/2) Power :400 watts wide-ranging, active Power Factor Correction, 90% Efficient Dimensions :447 x 178 x 455 mm (17.6 x 7 x 17.9 in) Weight :11.7 kg (25.8 lbs)