How to upgrade the memory of a 27-inch iMac with Retina 5K display (Late 2014 - Mid 2015) iMac15,1 - YouTube
Mac mini Late 2014] Ram upgrade | MacRumors Forums
Install memory in an iMac - Apple Support
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
iMac with Retina 5K Display 2014/2015 Memory Upgrades
Memory in New $1099 iMac is Soldered and Not Upgradable - MacRumors
Timetec Hynix IC 32GB KIT(4x8GB) Compatible for Apple 27 inch Mid 2010 21.5/ 27 inch Mid 2011 iMac DDR3 1333MHz PC3-10600 CL9 204 Pin SODIMM Upgrade for iMac 11,3 iMac 12,1 iMac 12, 2 (32GB KIT(4x8GB)) - Newegg.com
NEMIX RAM 16GB Kit (2x8GB Upgrade) DDR3-1600 SODIMM PC3-12800 for Apple MacBook Pro Mid 2012 / iMac Late 2012 / iMac 2013, Late 2014, Mid 2015, Mac Mini Late 2012 at Amazon.com
Install memory in an iMac - Apple Support
Apple 27" iMac with Retina 5K Display (Late 2014) Z0QX-MF8869
A-Tech 32GB Kit (4x8GB) RAM for Apple iMac (Late 2012, Late 2013, Late 2014, Mid 2015) | DDR3 1600MHz PC3-12800 SODIMM 204-Pin Memory Upgrade at Amazon.com
iMac with Retina 5K Display 2014/2015 Memory Upgrades
How to Install Memory iMac 27-inch 5K (RAM Crucial 16GB) - YouTube