Lenovo Desktop ThinkStation D20 2 x Xeon Six-Core 2.53GHz Bus Speed 5.86GT/s 12 MB Cache RAM 4GB 250GB SATA DVD Multiburner Gigabit Enabled (1.00 Gbps) Local Area Network Capable Quadro 4000 24-Pin Digital DVI-I Microsoft Windows 7 Professional (32-bit) License Only - No OS Installed U.S. English Tower Black