Can you upgrade the RAM in the 27-inch iMac? | iMore
Apple's 27" iMac Late 2012 model. How to upgrade the ram to 16GB - YouTube
Samsung ram Memory Upgrade DDR3 PC3 12800, 1600MHz, 204 PIN, SODIMM for 2012 Apple MacBook Pro's, 2012 iMac's, and 2011/2012 Mac Mini's (16GB kit (2 x 8GB)) at Amazon.com