CMS 12GB (3x4GB) DDR3 10600 1333MHZ ECC NON REGISTERED DIMM Memory Ram Upgrade Compatible with HP/Compaq® Workstation Z600 B3 SERIES DDR3 ECC For Server Only - B81 - Newegg.com
A-Tech 8GB Kit (2X 4GB) DDR3 1333MHz PC3-10600E 2Rx8 240-pin ECC-Unbuffered DIMM for HP Workstation Z200 and Z400 – Server Memory Ram Modules at Amazon.com
2X 4GB 2RX8 PC3-10600E 1.5V DDR3 1333MHz ECC Memory RAM Unbuffered for Server Workstation(4G) - Walmart.com