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 SODIMM PC3-12800 204-Pin SO-DIMM Max Memory Upgrade at Amazon.com
Apple iMac 27-inch (late 2012) Reviews, Pricing, Specs
Review: 27-Inch iMac 5K with i5 processor - 2012 on the outside, 2019 on the inside | AppleInsider