Amazon.com: Original Graphics Video Card for Apple iMac Core i7 2.8 27-Inch Late 2009 A1412 MC507LL/A MC507 Desktop Computer, AMD ATI Mobility Radeon HD 4850 GDDR3 512MB 109-B91157-00, GPU Upgrade Replacement : Electronics
Amazon.com: Original Graphics Video Card for Apple iMac Core i7 2.8 27-Inch Late 2009 A1412 MC507LL/A MC507 Desktop Computer, AMD ATI Mobility Radeon HD 4850 GDDR3 512MB 109-B91157-00, GPU Upgrade Replacement : Electronics
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 :
Upgrading the graphics in our 2011 iMac (first attempt) - YouTube
iMac Repair & Upgrade, Same Day Services
iMac 2009 / 2010 / 2011 GPU upgrade — Fixing LED/LCD PWM brightness with an ESP32 | by Fixing Things | Medium
iMac Intel 27" EMC 2374, AMD Radeon HD 4850 Video Card Removal & Repair - iFixit Repair Guide
2011 iMac Graphics Card Upgrade | How to | Mac Expert Guide
2010 iMac GPU Upgrade to NVIDIA GTX 765M - YouTube
Original Graphics Card GPU Replacement for Apple iMac 2009 Core 2 Duo 3.06 A1312 MB952LL/A 27 Inch Desktop PC Computer, ATI Mobility HD 4670 GDDR3 256MB 109-B80357-00, MXM Video Board Repair Parts: