iMac with Retina display review: best in class, but not everybody needs one | Engadget
iMac Retina 5K: Memory upgrade (RAM)
Install memory in an iMac - Apple Support
Install memory in an iMac - Apple Support
iMac (Retina 5K, 27-inch, Late 2014) - Technical Specifications
iMac with Retina 5K Display 2014/2015 Memory Upgrades
Upgrade your iMac's RAM in less than 5 minutes - YouTube
Apple 21.5" iMac All-in-One Desktop Computer (Mid 2014)
Timetec 32GB KIT(4x8GB) Compatible for Apple DDR3L 1600MHz PC3L-12800 CL11 for iMac (Mid 2011, Late 2012, Late 2013, Late 2014 Retina 5K, Mid 2015 Retina 5K) SODIMM Memory Module MAC RAM Upgrade at Amazon.com
How to Upgrade/Install Memory in a 21.5-inch iMac (Late 2012– Mid 2014) iMac14,1 iMac14,3 - YouTube