2011 21.5 Imac Graphics card.

[OlReg]

I've searched for some answers but haven't quite found the one I need.
A neighbor dropped off an older Imac. I'm thinking a 2011 21.5" model. It wouldn't boot past the initial loading screen and I think the graphics card has failed. I find replacement cards and the Radeon HD6750 M card is a direct replacement. I also see a 6770 M card and wonder if that offers any kind of better performance and if it's a direct replacement which will boot without any further creativity.
I'm mostly a PC guy and this is a MAC that I can fool around with for a while after I get it working again so that I won't worry about touching ANYTHING on my wife's Macbook pro.
I have replaced the motherboard on another neighbor's Imac a few years ago and I was way careful when I did.

 

[BrianBaughn]

This is where you should start:

2011 iMac Graphics Card Upgrade

iMac 2009 to 2011 MXM3 graphics card upgrade (Lastest update 10/13/2023 - this is the official documentation page - you found it finally!) This is the single and only documentation post. During the last years we constantly updated this post to reflect the lastet development of vBIOS and OCLP...

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