HP Z400, 2.66 GHz, Intel® Xeon® 3000 Sequence, W3520, 6 GB, DDR3-SDRAM, Windows 7 Professional HP Z400. Processor frequency: 2.66 GHz, Processor family: Intel® Xeon® 3000 Sequence, Processor model: W3520. Internal memory: 6 GB, Internal memory type: DDR3-SDRAM, Memory clock speed: 1333 MHz. Operating system installed: Windows 7 Professional. Power supply: 475 W. Chassis type: Minitower. Product type: Workstation. Weight: 19.6 kg