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 :
How I Fixed: Mid-2011 iMac Fans Running At Full Speed - Randy The Tech Professor
iMac 2009 to 2011 (A1311/A1312) Upgrade Guide – MacintoshMen
iMac Repair & Upgrade, Same Day Services
imac 27 mid 2011 cpu upgrade, Apple iMac - ciclomobilidade.org