HP Z400 CPU upgrade - HP Support Community - 5048908
CMS 8GB (2X4GB) DDR3 10600 1333MHZ ECC Non Registered DIMM Memory Ram Compatible with HP/Compaq Workstation Z400 Workstation for Server Only - B80 at Amazon.com
HP Z400 Workstation, Electronics, Computers, Desktops on Carousell
HP Z400 Workstation - Memory | HP® Customer Support
HP Z400 Workstation Memory Configuration and Optimization PDF | PDF | Workstation | Operating System
Micron 24GB 6x4GB PC3-10600E DDR3-1333 ECC Unbuffered DIMM F HP Z400 Workstation | eBay
OFFTEK 4GB Replacement RAM Memory for HP-Compaq Workstation Z400 (6 DIMM Slots) (DDR3-10600 - ECC) Server Memory/Workstation Memory at Amazon.com
Solved: Z400 RAM Upgrade from 8GB to 12GB or 16GB - HP Support Community - 6746942
Amazon.com: HP Z400 Workstation with Intel Xeon W3505 2.53GHz 2-Core CPU, 4GB DDR3 RAM, 250GB HDD, Quadro FX1700, Windows 7 Professional Installed : Electronics