How to Upgrade/Replace GPU Graphics Card on Mid-2011 21.5" iMac - YouTube
Amazon.com: Valley Of The Sun 2GB Graphics Video Card Upgrade for Apple iMac Mid-2011 27 Inch Core i5 MC814LL/A MC814 A1312 Desktop All-in-One PC, AMD Mobility Radeon HD 6970M Replacement Repair Parts :
Memory Upgrades for Apple iMac 2011 Up to 32GB
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