Amazon.com: OWC 16GB (2 x 8GB) PC8500 DDR3 ECC-R 1066MHz DIMMs Memory Compatible with Mac Pro Early 2009 & Late 2010 'Nehalem' & 'Westmere' Systems and Early 2009 Xserve. (OWC85MP3S8M16GK) : Everything Else
OWC 8GB PC8500 DDR3 ECC-R 1066MHz DIMM Memory Compatible with Mac Pro & Xserve 'Nehalem' & 'Westmere' Models (OWC8566D3MPE8GB) at Amazon.com