Hp Z 400 mixed ram - HP Support Community - 7621103
HP Z400 Workstation MT Intel Xeon W3550 3.07GHz 8GB RAM No HDD No OS
HP WorkStation Z400 ATX Xeon 3.2 GHz HDD 1 To RAM 8 Go
CMS 12GB (3X4GB) DDR3 10600 1333MHZ ECC Non Registered DIMM Memory Ram Upgrade Compatible with HP/Compaq® Workstation Z200, Z210, Z400, Z600, Z800 for Server Only - B81 at Amazon.com
4GB RAM Memory Upgrade for HP Workstation Z400 PC3-10600E DDR3 1333MHz 2Rx8 ECC Unbuffered UB DIMM Module (PARTS-QUICK Brand) at Amazon.com