iMac RAM upgrade: Here's an affordable way to improve multitasking - CNET
How to upgrade the RAM on the 27-Inch iMac (2020) | AppleInsider
OWC 16GB (2x8GB) ram Upgrade PC3-12800 DDR3L 1600MHz sodimm 204 Pin CL11 Memory Upgrade Kit Compatible with Late iMac, Mac Mini, and MacBook Pro Computer at Amazon.com
iMac RAM upgrade: Here's an affordable way to improve multitasking - CNET
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