CMS 8GB (2X4GB) DDR3 10600 1333MHZ ECC Non Registered DIMM Memory Ram Upgrade Compatible with HP/Compaq® Workstation Z400 Workstation for Server Only - B80
HP Z400 almost 48GB ram Upgrade + RamDisk Benchmarks - YouTube
HP Z400 Workstation Intel Xeon W3550 3.07GHz Quad Core, 18GB RAM, 1TB HDD, Win10 Pro FirePro,HP#4 - Desktop Computers - Citrus Heights, California | Facebook Marketplace | Facebook
SH693UC#ABA-07 - HP Desktop HP Z400 Workstation Xeon Quad-Core 3.20GHz — Tech Network Supply LLC
Refurbished HP Z400 4GB Computers - No Windows | Ultra Low Price!
HP Z400 Workstation W Intel Xeon W3520 @ 2.67GHz, 500 GB HD, 5 GB RAM, See Desc. | eBay