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
iMac 2009 to 2011 (A1311/A1312) Upgrade Guide – MacintoshMen
2010 iMac GPU Upgrade to NVIDIA GTX 765M - YouTube
Nueva tarjeta gráfica HD 6970M de 2 GB de repuesto para iMac mediados de 2011 de
iMac mid 2011 GPU upgrade | MacRumors Forums
Upgrading the graphics in our 2011 iMac (first attempt) - YouTube