CMS 12GB (3x4GB) DDR3 10600 1333MHZ ECC Non Registered DIMM Memory Ram Compatible with HP/Compaq Workstation Z600 B3 Series DDR3 ECC for Server Only - B81 at Amazon.com
Kingston Technology ValueRAM 4GB 1600MHz DDR3 PC3-12800 ECC Reg CL11 DIMM SR x8 with TS Elpida F Server Memory (KVR16R11S8/4EF) at Amazon.com