32GB (2x16GB) DDR3-1866MHz PC3-14900 ECC RDIMM 2Rx4 1.5V Registered Server Memory by NEMIX RAM at Amazon.com
CMS 8GB (2X4GB) DDR3 10600 1333MHZ ECC Registered DIMM Memory Ram Upgrade Compatible with Dell® Poweredge T620 Ddr3 Ecc Reg for Server Only - B37 at Amazon.com
OWC 24GB (3 x 8GB) PC8500 DDR3 ECC 1066MHz DIMMs Memory Compatible with Mac Pro Early 2009 & Late 2010 'Nehalem' & 'Westmere' Systems and Early 2009 Xserve (OWC85MP3W8M24K) at Amazon.com