2019 Apple Mac Pro vs. 2013 Mac Pro: How Far Has the Hardware Come? | PCMag
A-Tech 16GB Kit (2x8GB) RAM for Apple MacBook Pro (Mid 2012), iMac (Late 2012, Early/Late 2013, Late 2014, Mid 2015), Mac Mini (Late 2012) | DDR3 1600MHz PC3-12800 SODIMM 204-Pin Memory Upgrade at Amazon.com
iMac (21.5-inch, Late 2013) - Technical Specifications
Late 2013 27-inch iMac: Unboxing and Specs (HD) - YouTube
CMS 16GB (2X8GB) DDR3 12800 1600MHz Non ECC SODIMM Memory Ram Upgrade Compatible with Apple® iMac Core I5 3.4 27-Inch (Late 2013) Me089Ll/A - A7 at Amazon.com
New CPUs, faster Wi-Fi, same flaws: Apple's 2013 iMac reviewed | Ars Technica
Memory Upgrades for iMac 21.5-Inch 2012 - Late 2013
Install memory in an iMac - Apple Support
A pro with serious workstation needs reviews Apple's 2013 Mac Pro | Ars Technica