The optional Upgrades for the Apple iMac 27 are not worth it - NotebookCheck.net News
Maximum memory for 2011 iMac - Ask Different
Install memory in an iMac - Apple Support
Apple 24" iMac with M1 Chip (Mid 2021, Silver) MGPC3LL/A B&H
How to Upgrade iMac RAM: 2012-2022: EveryMac.com
Apple iMac review (21.5-inch, 2015): 4K is optional, faster hard drives shouldn't be | Engadget
Install memory in an iMac - Apple Support
Apple 21.5-inch iMac review | 2014 | Digital Trends
How to Upgrade iMac RAM (21.5" and 27" Aluminum): EveryMac.com
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