2 GB Graphics Video Card GPU Upgrade Replacement for Apple iMac Mid-2011 A1312 27 Inch Core i7 3.4 i5 3.1 Desktop Computer, New AMD Radeon HD 6970M HD6970M 2GB MXM Board Repair Parts
Apple Initiates Video Card Replacement Program for Radeon HD 6970M Equipped Mid-2011 27” iMacs
iMac 2009 to 2011 (A1311/A1312) Upgrade Guide – MacintoshMen
Upgrading an iMac GPU for METAL Support! Late 2009 – Mid 2011 Models - YouTube
iMac 27" mid-2011 GPU upgrade
iMac 2011 GPU Upgrade
2011 iMac Graphics Card Upgrade | How to | Mac Expert Guide