Amazon.com: 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 Repair
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Amazon.com: Original 1GB Graphics Card for Apple iMac 2010 27" Core i7 2.93 Desktop Computer MC784LL/A MC784 A1312, ATI Radeon HD 5750 GDDR5 1 GB Video Cards GPU Upgrade Replacement Parts : Electronics
iMac Intel 27" EMC 2390 Radeon HD 5750 Graphics Card