Amazon.com: 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
Late 2009 iMac 27" Video Card Repair — 4850 — 2nd Bake - YouTube
Amazon.com: 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 : Electronics
iMac 27" mid-2011 GPU upgrade
iMac Intel 21.5" EMC 2428 Radeon HD 6750M Graphics Card - iFixit Store
2011 iMac Graphics Card Upgrade | How to • Mac Expert Guide
Amazon.com: Original Graphics Video Card GPU Upgrade Replacement for Apple iMac 21.5 Inch Late 2011 Core i3 3.1 All-in-One Desktop PC MC978LL/A, AMD ATI Mobility Radeon HD 6750M, MXM VGA Board Repair