Gaming on a Cheap Xeon: The HP Z400 Workstation - Boiling Steam
HP Z400 Workstation - Memory | HP® Customer Support
HP Workstation Z400 Tower Desktop Computer PC, 2.60 GHz Intel Xeon Quad Core, 4GB DDR3 RAM, 2TB SATA Hard Drive, Windows 10 Home 64 bit (Refurbished) - Walmart.com - Walmart.com
OFFTEK 4GB Replacement RAM Memory for HP-Compaq Workstation Z400 (6 DIMM Slots) (DDR3-10600 - ECC) Server Memory/Workstation Memory at Amazon.com