Operating System :Windows 10 Home & Pro MAR, Ubuntu Linux, Free DOS Chipset :Intel C602 Processors :Intel Xeon E5-2600, Intel Xeon E5-2600 v2, Intel Xeon E5-1600, Intel Xeon E5-1600 v2 Memory Support :12 DIMM Slots for DDR3 ECC, 4-channel per processor 1066/1333/1600/1866 MHz DDR3, Up to 192GB Hard Drive :250GB to 3TB SATA 3.0-Gb/s, 300GB to 1.2TB SAS, 128GB to 512GB SSD Drives Removable Media :DVD-ROM/ DVD-ReWritable Expansion Bays :External: Two (2) 5.25-inch, Internal: Three (3) 3.5-inch Expansion Slots :2 PCIe x16 Gen3 Slots, 1 PCIe x8 Gen3, 1 PCIe x8(x4) Gen2, 1 PCIe x4(x1) Gen2, 1 PCI Slot Graphics :N/A Audio :Integrated Intel/Realtek HD ALC262 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, Audio I/O Input Devices :Standard Keyboard (USB or PS/2) Mouse (USB or PS/2) Power :800W Dimensions :44.45 x 17.15 x 46.48 cm Weight :17.9 kg