iMac A1312 - Upgrade to Big Sur

[leandro077]

Hello,

I have got multiple issues here.

I recently bought a iMac 27" from Mid 2010. The person I bought it from told me that the logicboard was broken, but showed me the GPU that was taken out by an "expert".
My first question is how can I find out if it's just the GPU or the whole logicboard that's broken?

Next question:
I wanted to upgrade the iMac to Big Sur. I realize that I need a metal GPU. I had the HD 8970m in mind as it is an MXM size and the most recent I can get.
As far as I understood this from the guides it will be compatible, but I won't have a bootscreen etc as it is not an Applecard. So I need to flash it right? Is there a flash available for this card? Or are there better options?

Thanks in advance

(And if the thread is in the wrong space, please move it or tell me to do so, I am always a bit confused in forums )

 

[EliteMacx86]

I recently bought a iMac 27" from Mid 2010. The person I bought it from told me that the logicboard was broken, but showed me the GPU that was taken out by an "expert".
My first question is how can I find out if it's just the GPU or the whole logicboard that's broken?

You can do a physical inspection of the logic board.

I wanted to upgrade the iMac to Big Sur. I realize that I need a metal GPU. I had the HD 8970m in mind as it is an MXM size and the most recent I can get.
As far as I understood this from the guides it will be compatible, but I won't have a bootscreen etc as it is not an Applecard. So I need to flash it right? Is there a flash available for this card? Or are there better options?

Yes, that's correct. The card needs to be flashed. A guide will be published very soon. Also, this will not boot Big Sur natively, you'll need to use OpenCore for that.