Further Explained: Apple's iMac 2011 Model Hard Drive 'Restrictions'
How to Upgrade iMac Hard Drive (2009, 2010, 2011): EveryMac.com
2011 IMAC SAMSUNG 1TB 850 PRO SSD UPGRADE - YouTube
OWC SSD Upgrade Kits for 27-Inch iMac 2011
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