Amazon.com: Valley Of The Sun New 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 :
For iMac 27" A1312 Mid 2009 2011 HD6970M upgrade NVIDIA GTX 765M 2GB Video Card | eBay
Amazon.com: 2GB Graphics Card GPU Upgrade Replacement for iMac 27 Inch Mid- 2011 A1312 Desktop Computer Core i5 3.1 MC814LL/A MC814, AMD Radeon HD 6970M GDDR5 2 GB MXM Video Board Repair Parts :
For iMac 27" A1312 Mid 2009 2010 2011 upgrade NVIDIA GTX 780M 4GB Video Card | eBay
Amazon.com: Sunvalley Original 2GB Graphics Card GPU Upgrade Replacement, for Apple iMac 2011 27 Inch A1312 i5 i7 Desktop PC Computer, for AMD Radeon HD 6970M 109-C29657-10 MXM Video Board Part : Electronics
Amazon.com: New HD 6970M 2GB Graphics Card Replacement for iMac Mid-2011 27" All-in-One Desktop PC Core i7 3.4 MD063LL/A MD063, AMD Radeon HD6970M HD6970 GPU Upgrade MXM Video Board Repair Parts :