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
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Amazon.com: Original Graphics Card GPU Replacement, for Apple iMac Late 2009 A1312 MC507LL/A 27-Inch Core i7 2.8 27-Inch Computer, AMD Radeon HD4850 HD 4850 GDDR3 512MB, MXM GPU Video Board Repair Parts :