Operating System :Windows 7 Home & Pro. MAR, Windows 10 Home & Pro MAR, Ubuntu Linux, Free DOS Chipset :Intel® PCH C206 Processors :Intel® Xeon? processor E3 family, 2nd gen Intel® Core™ processor family, Dual-Core Intel Pentium processors Memory Support :Four (4) DIMM slots for DDR3 PC3-10600 ECC, 16GB Max Hard Drive :250GB to 2TB SATA 3.0-Gb/s, 160GB 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: Three (3) 3.5-inch Expansion Slots :1 PCIe x16 Gen2 Slot, 1 PCIe x16 Gen2 (x4), 1 PCIe x8 Gen2 (x4), 2 PCIe x1 Gen1, 2 PCI Slots Graphics :Intel Integrated Graphics Media Accelerator HD Audio :Integrated Intel/Realtek HD ALC262 Audio Communications :Intel Gigabit CT Desktop NIC I/O Ports :Front: Three (3) USB 2.0, Headphone/Mic, Rear: Six (6) USB 2.0, 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)