How To: Upgrade 2017 5k iMac RAM to 64GB & Saved $840 | 2018 - YouTube
How do I add RAM to my iMac 5k 27-inch 2020, 2019, 2017 & 2015? - YouTube
Amazon.com: OWC 32GB (2 x 16GB) PC19200 DDR4 2400MHz SO-DIMMs Memory Compatible with Mac Mini (Late 2018), 27" and 21.5" iMac (Mid 2017), and Compatible PCs (OWC2400DDR4S32P) : Everything Else
OWC Confirms 64GB of RAM in Apple 27" iMac 2017
Apple 27" iMac with Retina 5K Display (Mid 2017) Z0TR-MNED43-BH
NEMIX RAM 64GB (4X16GB) SODIMM Memory Upgrade Kit DDR4 2400MHz PC4-19200 Compatible with Apple iMac
Adamanta 32GB (2x16GB) Memory Upgrade Compatible for 2017 Apple iMac 27" Retina 5K Display DDR4 2400MHz