Upgrading an iMac GPU for METAL Support! Late 2009 – Mid 2011 Models - YouTube
upgrade - Ordering a 21.5" iMac with a different graphics card - Ask Different
The New 2011 iMacs: Specs and Details
Apple opens graphics card replacement program for some mid-2011 iMacs - 9to5Mac
How to Upgrade/Replace GPU Graphics Card on Mid-2011 21.5" iMac - YouTube
iMac 2011 GPU upgrade to NVIDIA 770M with new VBIOS - YouTube
How to upgrade a Mac: Swap in new RAM, graphics card, hard drive and more | Macworld
Amazon.com: Original Graphics Video Card GPU Upgrade Replacement for Apple iMac 21.5 Inch Late 2011 Core i3 3.1 All-in-One Desktop PC MC978LL/A, AMD ATI Mobility Radeon HD 6750M GDDR5 512MB MXM Board :
iMac 2009 / 2010 / 2011 GPU upgrade — Fixing LED/LCD PWM brightness with an ESP32 | by Fixing Things | Medium
Original Ati HD 6970M 5750m 4850 4670 Graphics Card Video Card 1GB 2GB 109-C29657-10 For Apple iMac 27" A1312 GPU 2009 2010 2011 - AliExpress
Amazon.com: Original Graphics Video Card GPU Upgrade Replacement for Apple iMac 21.5 Inch Late 2011 Core i3 3.1 All-in-One Desktop PC MC978LL/A, AMD ATI Mobility Radeon HD 6750M GDDR5 512MB MXM Board :