Amazon.com: Yongxinsheng DDR3 4GBx2 (8GB Kit) 1600MHz PC3-12800 Desktop Memory CL11 240Pin 1.5V Non-ECC Unbuffered Compatible with All Motherboards UDIMM Ddr3 RAM - Black : Everything Else
48GB (3X 16GB) Matched Pair 1333MHz 240-Pin SDRAM DIMM DDR3 (PC10600) Memory Upgrade Kit for PC Desktops, Mac Pro 'Nehalem' & 'Westmere' (OWC1333D3X9M048) at Amazon.com