You are probably here because your 2011 iMac is having problems with its graphics card. Actually, it is well known that the 2011 iMac’s graphic card is quite problematic or defective. But, no worry, you can install another graphics card and get extra years out of your iMac. Read on to know more about 2011 iMac graphics card upgrade.
A Few Words Before Starting
Upgrading the graphics card not only makes your 2011 iMac more powerful but also allows you to use newer versions of macOS. Luckily, the 2011 iMac is easily upgradeable. You can take off the front screen and have access to the entire internals. This is way easier than how you do it on newer models, which involves using a heat gun to take off the screens.
However, you will need to extend macOS / Unix system administration knowledge, the ability to run programs from Terminal, and manual skills to re-assemble your iMac for this task.
Which Graphics Cards to Use?
Note that only Nvidia Kepler cards or AMD Ellesmere/Polaris cards will work in the 2011 iMac. Both of these will help you get full graphics acceleration with all current MacOS versions including macOS Big Sur. Additionally, there is no other GPU variant that has MacOS driver support.
Here is the list of recommended graphics cards:
1. NVIDIA Quadro K1100m
2. NVIDIA K2100m
3. NVIDIA K610m
4. AMD FirePro W4170
5. AMD FirePro W7100
The above graphics cards also support brightness control as well as boot screens via VBIOS flash. In this article, I will be attempting to upgrade from the factory 6770m to an NVidia K610m in my 2011 27-inch iMac. Personally, I think I would like to recommend this one because it’s very affordable ($14 on eBay). Plus, the chipset has already support from 10.8.3 onwards.
How to Upgrade 2011 iMac Graphics Card
Step 1: Taking Off the Screen

Starting by opening your iMac from the top, you can easily spot the vertical sync cable on the top left. Now, use your fingernail to pop it out and gently pull the cable away from the back of the computer. Moving onto the right side, look for the monitor cable and use your finger to slide it out from underneath. At the bottom of the screen, disconnect the power supply and camera cable with the same technique. After that, the whole monitor should pop out right away.
Step 2: Take the Motherboard out

You should need to undo the power supply to get the motherboard out. Also, just make sure to take a picture of all the cords and screws as you bring them out. I suggest putting your screws down in order, which makes sure you remember where to put them back. Here is the detailed guide for how to take the motherboard out on the 2011 iMac.
Step 3: Switching the Backplate

There are three screws that hold the heatsink and GPU to the board. Plus, you still have four more to actually remove the GPU from the heatsink itself. Now, you’re ready to take the GPU out.
Next, you will need to remove the backplate from the new GPU and switch it with the old one. We have to do this due to the screw size difference. Then, slowly push the screwdriver through the plate in order to push it out. Repeat this technique on both GPUs. Also, make sure you don’t bend the new one too much. After that, put the old backplate onto your new GPU. Also, remember to put some thermal paste on it.
Step 4: Assembling

If you’ve done everything correctly, then the assembling process would be quite easy here. However, note that you will lose the boot screen because the new graphics card only kicks when the operating system loads into the driver. On top of that, the brightness control also stops working from now simply because you don’t have the graphics card to support that function anymore.
The Bottom Line
Overall, if you like tinkering with computers, it’s absolutely worth it. There is still a lot of power in these old machines. And, I think they’re well faster than the 2019 MacBook Pros if you switch out the CPU or hard drive.
But, if you’re not familiar with this kind of task, then I wouldn’t recommend doing this yourself at all. Only a minor mistake can damage the hardware and that pretty much costs you around $100. So, in case you’ve never done this before, just get some local help in advance!
Let us know if you have any questions about how to upgrade the 2011 iMac graphics card in the comments!
Dear John,
I have some old iMacs I would love to upgrade for use at my children’s school. Problem is: I see all those manuals where they tell me I use this or that GPU because it’s so cheap. (you say you can buy the NVIDIA K610m for $14 on eBay) However I can’t find anything below $80 and some change for shipping. Please tell me the secret, or send me a link, or … No doubt that it’s completely due to my incapabilities, but I can’t find them. So again: please help me find something affordable. Thanks in advance from this European fan.
If I am using the Nvidia K2100m for this upgrade, will I have to modify the old backplate before I put it on the new card?
Unfortunately buying one of those cards cost more than buying an iMac of newer generation. You will have more performance, less trouble and you get the new iMac even cheaper than the entire upgrade.
iMac2011+upgrade > iMac 2013