Amazon.com: Original Graphics Video Card for Apple iMac 2011 Core i5 2.7 A1312 MC813LL/A MC813 27 Inch Desktop PC Computer AMD Radeon HD 6770M HD6770M GDDR5 512MB 109-C29557-00 Replacement Parts : Electronics
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 :
A1311 A1312 512mb 256mb Hd 6750 6750m Hd6750 2011 2010 Vga Video Graphics Card Gpu For Imac 109-c29557-00 216-0810005 661-5944 - Laptop Repair Components - AliExpress
Graphics Card - iMac 27″ A1312 (Mid 2011)
SOLVED: What GPU's are compatible with iMac 27" 2011? - iMac Intel 27" EMC 2429 - iFixit
Apple Initiates Video Card Replacement Program for Radeon HD 6970M Equipped Mid-2011 27” iMacs