How-To: Now's the right time to swap your old iMac's hard drive for a fast new SSD - 9to5Mac
2011 imac 27" 32GB - final stage of 1TB + 2TB SSD upgrade (replaced HDD & optic drive). Also cleaned out the fans and case. Running 'SSD Fan Control' & 'Macs Fan
iMac 27 "2020: SSDs arrive soldered - World Today News
OWC SSD Upgrade Kits for 27-Inch iMac 2011
1TB SSD Replacement Kit for Apple iMac 27" A1419 (Late 2015) : Amazon.co.uk: Computers & Accessories