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 32.0GB (2X 16GB) PC10600 DDR3 ECC-R 1333MHz 240 Pin Memory Upgrade Compatible with Select 2009-2012 Mac Pro Models (OWC1333D3X9M032) at Amazon.com
OWC 16GB PC8500 DDR3 ECC-R 1066MHz DIMM Memory Compatible with Mac Pro & Xserve 'Nehalem' & 'Westmere' Models (OWC8566D3MPE16G) at Amazon.com
Supermicro 16GB DDR3 MEM-DR316L-SL04-ER16 Server Memory
288GB (18 x 16GB) DDR3 PC3-10600 1333MHz ECC RDIMM Server RAM
IBM 77P8633 - 16GB PC3-8500 DDR3 ECC 1066MHz by IBM
HP 16GB PC3-12800 DDR3-1600 2Rx4 1.5v ECC Registered RDIMM (HP PN# 672612-081) at Amazon.com
HPE HP 664692-001 16GB PC3-10600 1333MHz CL9 ECC DDR3 SDRAM Server Memory Module - Integrity Global Solutions