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I recently got a 2010 27" iMac for free! Some further research concluded that the MXM slot in the iMac has been proven to work with a GTX 880m, including Mac OS! I used to play with a 7970 ghz edition, but ended up selling it for some more projects. I've been lagging along on a 5870 2gb and thought that with my switch to the free iMac, I might as well update my gpu. Heres the problem I was faced with: the 880m is a little underpowered on stock clocks. So, after even more research I discovered that the 980m was around the same as a 7970 performance wise. I ended up grabbing a deal on an 880m for only 160$, but I did want to share my findings with you guys.




So the 980m used to work all the way up to mac os sierra. It's now high sierra, but the fix is still pretty simple.


What you will need:

-thermal pads

-copper ram heatsinks/ one of the specialized backplates that cools MXM memory modules.

-Your graphics card

-YOU NEED an imac 2011 gpu heatsink

-GOOD thermal paste (Preferably liquid metal if youre comfortable with that)

-IMAC 2010 power supply

*As far as i know the power supply's between these 3 imac's are interchangeable, but the largest one is the 2010 variant, at the 310 watts, and the others are much lower.

*Just from tdp we know that the 980m is 115w and the cpu's on these guys are most commonly 95w, thats allready 200 with out hdd, all the other components etc.

-nvidia web drivers




Step 1: You must have all your mac os/ windows partitions set up with bootcamp, and MAKE SURE it boots into Mac OS and wont boot into anything else when you start it up AFTER the upgrade.

*Remember nvidia web drivers must be installed before you upgrae

Step 2: dremel/ cnc/ remove a couple parts of the VRM section of the imac 2011 heatsink, (You want your card IN HAND so you are able to make sure it fits correctly.

step 3: Assemble the gpu assembly

step 4: Re assemble the imac, with the new gpu.

*This is where is gets slightly harder*

step 5: You want to reset your iMac's System Management Controller, otherwise known as SMC.

*DO NOT FLASH NVRAM OR PRAM, or you will have to redo the whole process, after you put your old gpu in to fix all the bootcamp problems and such

*You can do this by plugging the power cord into your imac, waiting 30 seconds and NOT turning it on, unplug your power cord, wait 30 seconds, then plug it back in. Wait another 30 seconds, then turn it on. (But not before reading the following to be prepared:)

step 6: You need to force Mac OS to work with an unsupported card. this is a pretty simple process if you are comfortable with terminal.

* I couldn't have found this without this page: 



To make a non-apple provided Nvidia graphics card work in macOS Sierra you need to do the following…

Start the computer in safe mode by holding shift.

Get your BoardID by running this command in terminal

echo "<result>$(ioreg -rd1 -c IOPlatformExpertDevice | awk -F'["|"]' '/board-id/{print $4}')</result>"

Open the AppleGraphicsControl Kext using this command

sudo nano /System/Library/Extensions/AppleGraphicsControl.kext/Contents/PlugIns/AppleGraphicsDevicePolicy.kext/Contents/Info.plist

Use the arrow keys to go down until you see <key>ConfigMap</key> followed by a bunch of keys and strings.


IF IT IS LISTED: Change the string to <string>none</string>

IF IT IS NOT LISTED: Add it in the same format as the ones listed.

Save the file by pressing Ctrl+O, then enter.

Exit by pressing Ctrl+X

Rebuild the kernel cache using the following two commands:

sudo kextcache -system-prelinked-kernel


sudo kextcache -system-caches

Have Fun!


Theoretically this should work, and I would love for somebody to try as I got an 880m instead. Just keep in mind this is all from research and has not been proven to work. Be sure to research this subject before you try it.

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  • 6 months later...
  • 1 year later...

This was a good idea, but the problem is that the 980M is a Maxwell GM204 architecture. For the 2011 iMacs, only Kepler based GPUs will work (GK1xx). This has to do with the fact that Apple has not created any Maxwell (-Pascal or -Turing) based efi or legacy drivers to include in the GPU firmware. There was never any reason to, because they decided that their future would be AMD based GPUs and re-partnered up with AMD. 





Edited by nikey22
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  • 1 month later...

Is this still possible?


Is there a more comprehensive tutorial?

specifically based on your macOS or OSX you have

and their corresponding driver websites etc

and how to actually upload them

and where to store them directory and all that

and everything you have to do to prep your machine before getting all this done (for example: weather you NEED a windows partition etc)

and how to load the vbios on the actual GPU card (using what medium, whats the easiest way?)

does the GPU need a new heat sink (that's not apple) will it fit

do i need a power supply?


This is all very complicated for a noob like myself, even though i have the capability of learning how to do this (im not a noob really).  either way, I would appreciate some help as my computer with all my very expensive programs on it has been shit out of order for the past year and 5 months (yea since 2018)


1. i already purchased the GTX880M

2. I installed it before installing the drivers (smh)

3. I paid a professional to install it, and I am now going to have to pay him again to uninstall it


I'm lost.


I want to follow your guidelines but I can't even turn the computer on to install the drivers because installing the failed GPU would you cause the computer to freeze again..


please can you help me? beg you..


Any help is appreciated immensely appreciated and I can even paypal some money for the help if needed. thanks in advance 

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  • 3 weeks later...

Sorry, I just logged in now

Do you still have the GTX 880M installed in the imac?


The GTX880M WILL work in a 27" imac 2011, because it is a Kepler based GPU. But you will lose brightness control, which makes things very hot and bright, and probably make the fans spin up a bit more. I would recommend staying with High Sierra for now.


First lets gets some more information:

What year is your computer?

What size 27" or 21.5"?

What do you mean by I paid someone to install it? What did they exactly do? You can't install the GTX880M without a heatsink mod (slight shaving off of the inner corners); How did they test it? Did they just give it back to you?

You need a custom ROM for the GTX880M. Easily made. Did they flash some ROM in there? Probably not.

You need some skills like learning how to use a CH341a_spi programmer (this will help a lot getting out of trouble with a bad ROM)

You need to ID the flash ROM chip on the GPU board (easy)

Get familiar with how to disassemble the imac. Its not hard, but there are steps that need to be followed and lots of little connectors, a good source is ifixit.

You need flashrom for a linux based machine, like maybe ubuntu to do the flashing onto the ROM chip.


Lets start with that.





Edited by nikey22
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  • 3 weeks later...

Hi all,


This command doesn't like to be saved when entering all information:


sudo nano /System/Library/Extensions/AppleGraphicsControl.kext/Contents/PlugIns/AppleGraphicsDevicePolicy.kext/Contents/Info.plist


The error message is "operation not permitted" Even tried to remove the file and again the same message appears. The solution for this problem was not given by this tutorial.

I'm running O.S High Sierra.


According to the following link:



I need to run a command:


csrutil disable


But it seems I cannot enter the Recovery mode using Command + R. A stop sign occurs when trying to enter it.


Who is able to assist me?


With kind regards,

Edited by Kenny80
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