iMac 2011 GPU upgrade to NVIDIA 770M with new VBIOS - YouTube
Amazon.com: Sunvalley 2GB Graphics Video Card Replacement for Apple iMac Mid-2011 27 Inch A1312 Core i7 3.4 MD063LL/A MD063 Desktop PC Computer, ATI Radeon HD 6970 GDDR5 2 GB, New GPU Upgrade
Sunvalley 2 GB Grafikkarte GPU Upgrade Ersatz, für for Apple iMac Mitte 2011 A1312 27 Zoll