Memory RAM Upgrade for Apple iMac 27-inch Mid 2011 4GB/8GB DDR3 SODIMM
4GB DDR3 PC3-10600 1333MHz 204-pin SODIMM. 8GB DDR3 PC3-10600 1333MHz 204-pin SODIMM. This iMac officially supports 16GB maximum (4 x 4GB). This upgrade will NOT invalidate your system warranty. Price is for a single module only.