Upgrading an iMac GPU for METAL Support! Late 2009 – Mid 2011 Models - 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 :
Burn the VGA and Fix your iMac - Don't Pay Shitty Problems!!! - YouTube
Amazon.com: Tarjeta gráfica original GPU de repuesto para Apple iMac A1311 Mid-2011 Core i5 2.7 MC812LL/A MC812 computadora de escritorio de 21,5 pulgadas, AMD Radeon HD 6770M GDDR5 512MB piezas de reparación :