6GB KIT (3 x 2GB) for HP-Compaq Z Workstation Series Z400 (6 DIMM Slots). DIMM DDR3 ECC Unbuffered PC3-10600E 1333MHz Server Ram Memory. Genuine A-Tech Brand. at Amazon.com
6GB 2GB x3 Sticks DDR3 Samsung and Hynix PC3-10600R Registered Server Ram | eBay
6GB RAM (3) 2GB Server Memory 2Rx8 PC3-10600R IBM DDR3 SDRAM Low Profile | eBay
CORSAIR XMS3 6GB (3 x 2GB) DDR3 1600 (PC3 12800) Desktop Memory Model TR3X6G1600C8 G - Newegg.com