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
16GB 1866Mhz PC3-14900R 2RX4 DDR3 ECC Registered Server Memory
Samsung 16GB DDR3-1600 ECC Registered Server Memory M393B2G70QH0-CK0 at Amazon.com
192GB (12 x 16GB) DDR3-1866 MHz PC3-14900R ECC– Cloud Ninjas
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
00D4970 IBM 16GB DDR3 PC3-12800 CL11 ECC DDR3 Memory
IBM 77P8633 - 16GB PC3-8500 DDR3 ECC 1066MHz by IBM