64GB Memory Upgrade for 2019-2020 Apple iMac (27-inch)
Apple iMac 27 5k retina core i5 3.7 GHz, 40GB RAM, Pro Radeon | eBay
Apple 27" iMac® with Retina 5K display (Latest Model) Intel Core i7 (3.8GHz) 8GB Memory 512GB SSD Silver MXWV2LL/A - Best Buy
A-Tech 16GB (2x8GB) RAM For 2019 IMac 27 Inch Retina 5K, 2018 Mini DDR4 2666MHz | eBay
NEMIX RAM Compatible for 128GB (4x32GB) DDR4 2666MHz PC4-21300 SODIMM Memory Upgrade for Apple iMac Mid 2020 (iMac 20,1/20,2) / Mid 2019 (iMac19,1) 27-inch w/Retina 5K, Late 2018 Mac Mini 8,1 at Amazon.com
Factory Original 64GB (2x32GB) Memory Upgrade for 2020 & 2019 Apple iMac 27" w/Retina 5K Display & 2018 Apple Mac Mini DDR4 2666Mhz PC4-21300 SODIMM 2Rx8 CL19 1.2v RAM Adamanta at Amazon.com
Compared: 2018 i9 MacBook Pro versus iMac 5K performance | AppleInsider
Factory Original 64GB (2x32GB) Memory Upgrade for 2020 & 2019 Apple iMac 27" w/Retina 5K Display & 2018 Apple Mac Mini DDR4 2666Mhz PC4-21300 SODIMM 2Rx8 CL19 1.2v RAM Adamanta at Amazon.com
Timetec Hynix IC 32GB KIT(2x16GB) Compatible for Apple 2019 iMac 27-inch w/Retina 5K Display, Late 2018 Mac Mini DDR4 2666MHz PC4-21300 2Rx8 CL19 1.2V SODIMM Memory RAM Upgrade (32GB KIT(2x16GB)) - Newegg.com
Adamanta 16GB (1x16GB) Memory Upgrade for 2020 Apple iMac 27" w/Retina 5K Display, 2019 Apple iMac 27" w/Retina 5K Display, 2018 Apple Mac Mini DDR4 2666Mhz PC4-21300 SODIMM 2Rx8 CL19 1.2v DRAM
iMac Retina 5K: Memory upgrade (RAM)
Apple iMac 27-inch (2020) Review | Trusted Reviews
Best Buy: Apple 27" iMac® Intel Core i5 (3.2GHz) 8GB Memory 1TB Hard Drive Silver ME088LL/A