16.0GB OWC Memory Upgrade Kit - 4 x 4.0GB PC8500 DDR3 ECC 1066MHz 240 Pin
16GB (4x4GB) DDR3 ECC PC8500 1066MHz SDRAM PC3-8500 ECC for Mac Pro & Xserve 'Nehalem' & 'Westmere' models:  Mac Pro 8-Core Mid 2010-2012, Mac Pro Quad-Core Mid 2010-2012, Mac Pro Early 2009 8-Core, Mac Pro Early 2009 Quad-Core, Xserve 9-Core Early 2009, Xserve Quad-Core Early 2009. OWC Memory for Mac Pro Quad Xeon fully meets Apple's specifications w/ special attention to proper thermal specifications.  Also compatible w/ Intel/AMD Process based PCs. Memory compiles with JEDEC Specifications, document JESD79-3B.