iM 4,1-14,4 2011 iMac Graphics Card Upgrade

[archer75]

Edit - I found a repair service on ebay. You send them your card and they replace the GPU and send it back. 6 month warranty. They have 100% positive feedback. If they can't fix it they refund the money. $155. Anyone use one of these services?

replace the GPU chip? in most of the cases , it is reballing the GPU to the card.and in most cases is will work, but it may not last too long.[/QUOTE]

Correct. They have 2 services. A cheaper one that is reballing the chip and provides a 90 day warranty and this one that replaces the gpu for a new one and has a 6 month warranty.

 

[yifuhood]

I am not a export on GPU Chips, but sound card, amplifier I do know something, it is similar at this point.
it all come down to if the replacing Chip is a good Chip, and how well the soldering has done, what kind of soldering equipment they use.
ask apple how much it will cost you. compare

 

[Lxixboss]

What exactly is meant by "no brightness" controls? Is the screen just on full brightness all the time, with no way to change it?

Well, I don't know if the brightness is on full but it definitely cannot be adjusted (as far as I can tell, anyway). This is a frequent consequence of using unflashed PC video card in a Mac (common in Mac Pro circles). I am presently sitting at my kitchen table typing this out on the Imac and the screen brightness is just fine... it just can't be adjusted.

 

[T'hain Esh Kelch]

Well, I don't know if the brightness is on full but it definitely cannot be adjusted (as far as I can tell, anyway). This is a frequent consequence of using unflashed PC video card in a Mac (common in Mac Pro circles). I am presently sitting at my kitchen table typing this out on the Imac and the screen brightness is just fine... it just can't be adjusted.

Okay, good to know. I don't like my screen on a very high brightness setting, but maybe I can live with Shades in that case.

 

[archer75]

I am not a export on GPU Chips, but sound card, amplifier I do know something, it is similar at this point.
it all come down to if the replacing Chip is a good Chip, and how well the soldering has done, what kind of soldering equipment they use.
ask apple how much it will cost you. compare

apple is $600+, not an option. Plus the repair service warranties their work. If the repair doesn't work they refund your money. In terms of equipment they say:
Unlike most other “repair services” that use heat guns, blow torches & inferior Chinese, light bulb, infrared machines, the equipment we use to fix your computer costs thousands of dollars, is of the highest quality German Black Infrared heating elements and is computerized itself which assures a professional and correct fix for the issue. Most other “repair” services fail again quickly.

 

[Lxixboss]

Okay, good to know. I don't like my screen on a very high brightness setting, but maybe I can live with Shades in that case.

About "Shades"; when I tried to run it, I got an error where it seemingly was not able to "connect with Shades". I got something called "Brightness Slider" from the App Store. It's free and seems to run perfectly. Like its name implies, it gives you a brightness slider on the menubar much like the volume control... now, if I could only get a boot screen.

 

[Johnny.ego]

I've purchased from a local auction a not booting iMac mid 2011 for few euros. Externally perfect, internally was missing hdd and ram. Powering on, the di

I've purchased from a local auction a not booting iMac mid 2011 for few euros.

Externally perfect, internally was missing hdd and ram.

Powering on, the display stays black and the fan start spinning and 1 beep every 5 seconds.

Added one dimm of 2Gb ddr3 10600 non ecc un buffered on one of the upper slots (the ones close to the screen), the beeps are gone but still black screen and no boot sound.

Added a sata disk, a wired keyboard, a USB install disk of Yosemite and plugged to an external hdmi monitor to the thunderbolt port with an adapter and still black screen and no boot sound.

Diagnostic led 1 and 2 are lit, 3 and 4 not.

How can I determine if it is:

1) AMD 6750 dead

2) Motherboard dead

3) PSU not powering AMD GPU

4) Something else

 

[archer75]

You can test the PSU with a multimeter. Pretty easy to do.

 

[amd is the best]

Just read this thread top to bottom. Lots of incredible findings and effort!

What would you all advise would be my best option for my Mid 2011 27" i7 6970M 1GB that has just had it's graphics card fail (pretty sure)?

1. Get 6970m 1gb
2. Get 6970m 2gb?
3. GTX680M and deal with the side affects?
4. Other?
5. New iMac?

When I power my iMac on, tone happens, it displays the apple logo and five vertical transparent blue lines, then shows the loading bar for a moments then just goes white. Can you confirm this is the video card?

If I leave the power cable disconnected for an extended period of time sometimes it will allow me to boot up.

 

[T'hain Esh Kelch]

I got the famous "green lines over the screen" problem with my 2011 iMac, meaning my Radeon 6970M 2GB was dead. Boo!

After much deliberation, I took the machine apart, got the graphic card out, cleaned it (Look at the amount of goo on that one!), gave it a nice cooking in the oven (8' @ 200°C), reapplied (Much less!) thermal paste and reinstalled everything. And what do you know? 8)

Yes I do need to clean that oven.

It is alive!!!!

Now, hopefully it will last quite a while.. I will stress test it this weekend. It is not perfect, as I have seen a dock icon jump weirdly and starting in recovery mode produce a weird white line on the left side of the screen, but at least the machine is booting now!

 

[wlaro]

is possible to install a gtx 960m (type A) inside imac 2011 21.5' or better pick up a gtx 765m?
(i see on this topic some successful)

 

[Fede49]

Hi, i am new here!
Im going to upgrade my graphic card ON my iMac 21.5 mid 2010 i3 3,2 16gb RAM . Ive an ati hd 5670 512mb and im going to put a gtx 680m 4gb. I work with video editting and i need more gpu to render.
I know What i must to do to replace them, but i need to install drivers before or something?
I read in this post someone works but i dont know more...

Can somebody help me with this?

Sorry for my bad english and thx very much!

 

[digdagdigedag]

Hi MichaelDT,
Does your iMac 2011 with the ugraded graphic card still work ?
I found a brand new

- GeForce GTX 680M MXM 3.0 Type B (for 300 US$) and a
- NVIDIA QUADRO K3000M 2GB MXM (for even 155 US$)

but have no clue if I can use them to replace my dead video card.

Can you give me some hints on what to look for ?

What about those issues with the boot screen ? Is there anythong I can (or have to) do ?
Thanks a lot


[iMac 27'' , Mid 2011 , AMD Radeon HD 6770M 512kB]

 

[Fede49]

My card upgrade works perfect, only i loose de bootscreen i cant use de minidisplay port? Anybody knows what can i do to fix The problem with the minidisplayport?

Thx

 

[MichaelDT]

Hi MichaelDT,
Does your iMac 2011 with the ugraded graphic card still work ?
I found a brand new

- GeForce GTX 680M MXM 3.0 Type B (for 300 US$) and a
- NVIDIA QUADRO K3000M 2GB MXM (for even 155 US$)

but have no clue if I can use them to replace my dead video card.

Can you give me some hints on what to look for ?

What about those issues with the boot screen ? Is there anythong I can (or have to) do ?
Thanks a lot


[iMac 27'' , Mid 2011 , AMD Radeon HD 6770M 512kB]

It does still work, power is a problem on the 21" though, I blanked the power pins and ran secondary lines to an external power supply so it doesn't tax the PSU during games. I guess theoretically I could just change out some caps and inductors on the iMac PSU and up the output, but then I'd have to do a bunch of circuit analysis and that's no fun.

I can not be sure that any graphics card will work due to many manufacturers making non mxm standard modifications to hardware and firmware. It will take any standard mxm card from a UEFI compatible machine as is required by the mxm-sig. You will want to have Nvidia drivers installed beforehand and check that the chipset is supported. The best way to do this is to check if the card is supported in macOS is if it works on people's hackintosh laptops. The only real way to know is to try it of course. As for the boot screen, if you had the time you could flash the card with firmware you edited to make it enumerate properly on EFI, but that is very very time intensive and you'd better know how to program embedded devices.

If I were still tinkering at this point I'd just build a mxm to pcie converter run a ribbon cable out of the case to it and use a pcie graphics card power by en external psu. It's been done plans are on the net. With a flashed card from Mac vid cards would likely work perfectly.
[doublepost=1493747688][/doublepost]

My card upgrade works perfect, only i loose de bootscreen i cant use de minidisplay port? Anybody knows what can i do to fix The problem with the minidisplayport?

Thx

Are you using MDP to HDMI or MDP to D-SUB/VGA? Usually it will not work with HDMI, you can edit some hex tables and get it to work usually but updates will wipe it and often you have to start from scratch as Apple likes to rewrite drivers.

Lesson: Try D-SUB/VGA

 

[rivermandan]

Let me step in here and give you guys some info as a person who fixes dead mac logic boards for a living.

1) DO NOT PAY SOMEBODY TO FIX YOUR DEAD ATI CARD, IT IS ALL COMPLETE ********. yes, there is nothign wrong with the BGA on your GPU, the problem is with the GPU itself. the reball is not the reason the card works again thereafter, it only works again because you have heated the GPU up to rework temperature which literally warps the die back into shape.

2) for this same reason, DO NOT PAY SOMEBODY TO REPLACE YOUR GPU ITSELF. there has not been a source for replacement 216-0811000 chips at all. I have tried various sources, as have all the other people in my industry, and the only thing you can find are USED REBALLED GARBAGE being sold as "brand new". they literally polish off the old markings on the GPU so it looks new, then print/engrave fake date codes onto the things, but if you have a good microscope, you can see the signs of this. so with these new chips, when you install them onto a board, they will work again because THE DIE HAS BEEN BROUGHT TO REWORK TEMPERATURE. with laptop chips, you can often get used rebaled chips like this with a bit of life into them, but 100% of these desktop chips have been pulled off of their PCB because THEY DIED. so you will be getting a chip that will work for a few months then take a ****.

3) DO NOT PUT YOUR CHIP IN THE OVEN, OR BLOW IT WITH A HEATGUN AND THINK YOU ARE GOING TO HAVE A PERMANENT SOLUTION. yes it will often bring your card back to life because it warps the die back into shape, but it will fail again if you put the card under any load. you can squeeze a few years out of it if you give it the old "reflow" (tip: if you are doing this with a heatgun, you aren't going anywhere close to rework temperature. at reflow temperature, you can gently poke the chip and it will feel like it is attached to teh board by jello. if it's hard as a rock, which it always will be because there is a reason we use 2000watt rework machines on multilayer PCB, it isn't molten, and you sare actually weakening the solder joints.), and don't put the GPU under real load again, but if you want to game, don't even bother

4) DO NOT BUY REPLACEMENT APPLE CARDS ON EBAY FROM CHINA. they are 100% just "reflowed" garbage. they will last a few weeks/months then take a ****. THERE ARE NO PEOPLE PULLING THESE CARDS FROM WORKING SYSTEMS, BESIDE A HANDFUL OF PEOPLE UPGRADING THEIR CARDS LIKE IN THIS THREAD. it is not worth the gamble.

5) ESPECIALLY DO NOT BUY A 6970. seriously, I feel really sorry for you guys that just "upgraded" a 6770 that may have given a few more years of life to a 6970 that will **** out in a matter of weeks/months under any load. even if the card was a legitimate pull (pro tip: it wasn't, I don't care what the seller said or how well you think it's working, *it wasn't*), it will still cook itself to death sooner than later. your best bet if you DID buy one of these cards is to use something like macsfancontrols to keep the optical drive and HDD fan running at 80% constantly, or even better (and yes, I realize this sounds a bit crazy), cut a window in the back of the mac right above where teh GPU heatsink is. if oyu can keep these cards under 70 degrees under load, they are FINE, but at 80-90, ticking time bomb.

anyhow, I hope I saved some of you guys some wasted time and money with that one, though I'm sure the lot of you are, like me, too stubborn to be told why not to do something until you do it yourself and learn first hand why not to bother doing it ($200 in 216-0811000 later, lol). the reason I am in here is because I'm trying to find an inexpensive, RELIABLE solution to bringing these 2009-2011 imacs back to life so I can turn the pile of dead units I have into cash. I'm not there yet, but I'm scoping out the cheap lineup of quattro cards and thinking an apple geforce flash might work. I'll update this thread as I go, regardless if I succeed or throw in the towel.

 

[Double-G]

My 6970m that was reballed by computer-Systems.gr about half a year ago just died completely. The LED on the motherboard stays dark, no GPU detected anymore.

Now I'm in desperate need for a new GPU. As @rivermandan pointed out old crap is not the way to go.
We need to find a mxm card that can be bought for cheap and flashed with a proper bios to get Bootscreen, brightness and of course output to the internal Display working. My aim is Windows/Bootcamp.
This is not about Performance, I simply want my iMac to be usable again and prevent it from becoming trash.

 

[rivermandan]

My 6970m that was reballed by computer-Systems.gr about half a year ago just died completely. The LED on the motherboard stays dark, no GPU detected anymore.

Now I'm in desperate need for a new GPU. As @rivermandan pointed out old crap is not the way to go.
We need to find a mxm card that can be bought for cheap and flashed with a proper bios to get Bootscreen, brightness and of course output to the internal Display working. My aim is Windows/Bootcamp.
This is not about Performance, I simply want my iMac to be usable again and prevent it from becoming trash.

if you don't need a boot screen (I don't know why everyone is going the screen sharing route; turn on your mac, hold "t", connect a tbolt cable to another mac and install it that way), there are semi-reliable cards that seem to work, but I'm looking for a cheap card that I can buy in bulk and flash so I can turn otherwise garbage imacs into machines I can sell.

also, unless computer-systems.gr are legitimately stupid and hilariously went through the effort of reballing your chip, they likely just gave it a reflow. all of those services are either smart *******s scamming people, or legitimately stupid people unintentionally misleading customers.

either way, for the five seconds it takes to google search what the actual problem is, it is unacceptable

 

[MrBat]

Let me step in here and give you guys some info as a person who fixes dead mac logic boards for a living.

1) DO NOT PAY SOMEBODY TO FIX YOUR DEAD ATI CARD, IT IS ALL COMPLETE ********. yes, there is nothign wrong with the BGA on your GPU, the problem is with the GPU itself. the reball is not the reason the card works again thereafter, it only works again because you have heated the GPU up to rework temperature which literally warps the die back into shape.

2) for this same reason, DO NOT PAY SOMEBODY TO REPLACE YOUR GPU ITSELF. there has not been a source for replacement 216-0811000 chips at all. I have tried various sources, as have all the other people in my industry, and the only thing you can find are USED REBALLED GARBAGE being sold as "brand new". they literally polish off the old markings on the GPU so it looks new, then print/engrave fake date codes onto the things, but if you have a good microscope, you can see the signs of this. so with these new chips, when you install them onto a board, they will work again because THE DIE HAS BEEN BROUGHT TO REWORK TEMPERATURE. with laptop chips, you can often get used rebaled chips like this with a bit of life into them, but 100% of these desktop chips have been pulled off of their PCB because THEY DIED. so you will be getting a chip that will work for a few months then take a ****.

3) DO NOT PUT YOUR CHIP IN THE OVEN, OR BLOW IT WITH A HEATGUN AND THINK YOU ARE GOING TO HAVE A PERMANENT SOLUTION. yes it will often bring your card back to life because it warps the die back into shape, but it will fail again if you put the card under any load. you can squeeze a few years out of it if you give it the old "reflow" (tip: if you are doing this with a heatgun, you aren't going anywhere close to rework temperature. at reflow temperature, you can gently poke the chip and it will feel like it is attached to teh board by jello. if it's hard as a rock, which it always will be because there is a reason we use 2000watt rework machines on multilayer PCB, it isn't molten, and you sare actually weakening the solder joints.), and don't put the GPU under real load again, but if you want to game, don't even bother

4) DO NOT BUY REPLACEMENT APPLE CARDS ON EBAY FROM CHINA. they are 100% just "reflowed" garbage. they will last a few weeks/months then take a ****. THERE ARE NO PEOPLE PULLING THESE CARDS FROM WORKING SYSTEMS, BESIDE A HANDFUL OF PEOPLE UPGRADING THEIR CARDS LIKE IN THIS THREAD. it is not worth the gamble.

5) ESPECIALLY DO NOT BUY A 6970. seriously, I feel really sorry for you guys that just "upgraded" a 6770 that may have given a few more years of life to a 6970 that will **** out in a matter of weeks/months under any load. even if the card was a legitimate pull (pro tip: it wasn't, I don't care what the seller said or how well you think it's working, *it wasn't*), it will still cook itself to death sooner than later. your best bet if you DID buy one of these cards is to use something like macsfancontrols to keep the optical drive and HDD fan running at 80% constantly, or even better (and yes, I realize this sounds a bit crazy), cut a window in the back of the mac right above where teh GPU heatsink is. if oyu can keep these cards under 70 degrees under load, they are FINE, but at 80-90, ticking time bomb.

anyhow, I hope I saved some of you guys some wasted time and money with that one, though I'm sure the lot of you are, like me, too stubborn to be told why not to do something until you do it yourself and learn first hand why not to bother doing it ($200 in 216-0811000 later, lol). the reason I am in here is because I'm trying to find an inexpensive, RELIABLE solution to bringing these 2009-2011 imacs back to life so I can turn the pile of dead units I have into cash. I'm not there yet, but I'm scoping out the cheap lineup of quattro cards and thinking an apple geforce flash might work. I'll update this thread as I go, regardless if I succeed or throw in the towel.

Hi,

I got my 6970 2GB professionally reballed exactly 1 damn year ago. The grey lines just started appearing again when stressing the GPU...

I dearly love my imac 27" 2011 and I've been researching google up and down to find an alternative MXM card that just works, or one that require some reflashing to make the boot appear, so I can easily switch at boot to Windows or macOS.

Is there any option to out there?

--

To be mentioned, I drive 2 additional screens from the imac, so, a full compatible replacement is what I'm looking for.

I saw some folks trying with GTX 880M and GTX 770M but they lost the bootload. Also, seems like even if a card has an UEFI BIOS, like some Clevo or Alienware do, it does not help to get bootload.

 

[Lost Heaven]

"but at 80-90, ticking time bomb"

Couldn't help chuckling after reading that: it happens to be what I said, word for word, to a Genius Bar guy after he informed me that my iMac wouldn't be fixed under Apple's recall program and as I was arguing that the problem occurred not from misuse, as he suggested, but from a latent fault in the GPU that is bound to manifest itself sooner or later in any model with the 6970.
The irony of this is that those who spent less money on a 2011 model probably still have them running today, while those who actually spent more and went with the highest-priced models with the 6970, had them fail.
So you end up having been more profitable to the company and not having anything to show for now.

the reason I am in here is because I'm trying to find an inexpensive, RELIABLE solution to bringing these 2009-2011 imacs back to life so I can turn the pile of dead units I have into cash. I'm not there yet, but I'm scoping out the cheap lineup of quattro cards and thinking an apple geforce flash might work. I'll update this thread as I go, regardless if I succeed or throw in the towel.

While I don't repair Macs for a living like you do, allow me to chime in as someone who spent a good few months trying to do the same thing, and say that you're in for a true time-sink. No combination of MXM GPUs, flashed BIOS, display drivers and/or OS versions that I tried yielded anywhere near the same functionality/stability that the stock one did.

From my own personal experience trying to make my 2011 iMac simply usable again, as well as everything that I've learned from having read every single one of the 694 posts in this thread as well as feedback gotten from chatting with other users who did the same, I'm now convinced that, if you own a 2011 iMac with a failed 6970, you can summarise your options to the following:

• if you want your iMac to perform exactly the same way as it did before its 6970 failed, you'll have to resign to parting with whatever money Apple charges (over £300, in my case) to fix it themselves. I believe this is the only way that you can get a new 6970 in your system, with some sort of warranty (1 year, I believe?).
  I can't possibly consider this a valid solution since, as @rivermandan pointed out, this GPU is a ticking time bomb. It has a design flaw that will manifest itself sooner or later. You can be lucky, and have it develop while under warranty and have Apple replace it for free. But, more likely, it will happen after that first year, and you'll be back to square one after having wasted a tremendous amount of money.
  
  
• if you want your iMac to perform exactly the same way as it did before its 6970 failed, but you can't afford or don't want to spend the amount of money Apple charges for a new 6970, you can buy a used one for about one third of the price.
  This is even less of a valid option since, as I pointed out, a used one is even likelier to fail (and will fail). As if that isn't enough of a deterrent, they're rare and hard to find.
  
  
• if you want your iMac to perform exactly the same way as it did before its 6970 failed, but can't afford to spend a huge amount of money trying to solve this, you can try to have it reflowed like @T'hain Esh Kelch kindly reminded me. Last time I checked in the UK this should cost around one sixth of what Apple charges for a new one, but you have no guarantees that it will work. Even when it does, it is a matter of time until the GPU fails again, determining factors being how much you push it and the quality of the job. I understand that, if you're lucky, you might find someone who will only charge you on a successful reflow (don't quote me on this).
  Also, if you have the guts/knowledge, you can always try to do the reflow yourself, with the obvious advantage that this won't cost you anything and you might as well try to get something out of an otherwise useless component.
  
  
• if you're willing to part with or don't need certain functionalities, such as the boot screen and native brightness control, you can buy an MXM GPU pulled from a non-Apple system. You'll have to rely on reports by other users who successfully took this route to determine which cards are compatible. Not only will you have to search for a certain model, you'll also need to find specific brands and BIOS versions. Any mismatch in those combinations will make it unusable in your iMac. As a consequence, finding one of these cards takes a considerable amount of time.
  You may have to perform physical modifications on your heatsink as some cards won't fit in it as the 6970 does.
  This does have the benefit of giving you a performance boost, provided the card you buy is more powerful than the 6970.
  I have to reinforce that this is only a valid option if you are positive you are happy to part with the boot screen and brightness control. From my experience, depending on which card you get, your system will also likely be less stable than it was with the stock GPU, with the occasional crash, freeze or boot into a white or black screen.
  Any macOS update comes with the risk that it may stop working with the card.
  If you use BootCamp, it may also not work with Windows. Even when it does, finding working drivers for it may be hard or even impossible (in which case, you do have the option of modding them yourself, at least). I noticed that in Windows (couldn't find out on macOS), some cards, such as the 780M, have their clock speeds locked and won't run at full performance. Even manually editing and flashing a BIOS, making sure the clocks were unlocked and maxed out, didn't work, in my case.
  Having taken this route, I was surprised to find out that I couldn't cope with the loss of brightness. Apparently, some people are less sensitive to this than others. No brightness control app that I've tried managed to have the same effect that the native one did with the stock GPU, simply because they don't control the brightness at all: they simply apply some sort of filter that tints the screen darker or lighter. Actual brightness never really changes. This is easy to observe on a dark room. I found that this makes the image dull and couldn't cope with it. You may not be as sensitive to this.
  
  
• if you can't afford to lose functionality but are happy to lose performance, you can buy a used GPU pulled from a pre-2011 iMac. I haven't tried this route personally, so I can't vouch for it, but it should work: the OS should have native drivers for it, boot screen and brightness control should remain functional and everything else should work as it did with the 6970, with the obvious performance loss, as all pre-2011 iMac GPUs are less powerful than it.
  This option still has the drawback that you can't buy a new GPU. They're simply not available. Any listing describing them as new is either inaccurate or false. You're forced into buying a used one, pulled from an older iMac. It will always be a gamble, as you can't tell how the previous owner used it; how much stress it has been through. It can fail, albeit at a much lesser rate than a 6970, considering both cards have been given similar usages. Also, as if this wasn't enough, I've also read reports that other GPUs used on pre-2011 iMacs are also prone to failing, with similar symptoms to the 6970, so there will always be some risk associated to this route.
  All in all, if performance is important to you, then this isn't a valid option at all, since the drop from a 6970 to any pre-2011 iMac GPU is very noticeable.
  If you, however, just need your iMac to be usable again and the performance loss won't matter, I'm convinced this is still the best option available to you.
  I would still love to hear from any owner who took this route and report on his experience.
  
  
• I'm only going to mention this possibility for the sake of accuracy, but it really isn't worthwhile due to their obscene price right now, but an external GPU would also bring the iMac back to life. You won't, if what I've researched is correct, get image from its internal display, so you would be limited to external ones anyway, which further diminishes this option's viability.
  
  
• I have also unsuccessfully attempted a seventh option, which was to disable the iMac's discrete GPU by deleting its driver files and try to make it work with the GPU that's integrated in Intel's CPUs. This is way beyond my comprehension, and I can only imagine that the integrated GPU is either disabled or unaccessible, and I was never able to pull it off. This was done by following the same instructions for disabling the discrete GPU on MacBook Pros and using their integrated ones: https://web.archive.org/web/2017020....edu/~zc227/extras/early2011mbp_graphics.html
  Even if this worked, you should expect the system to function with a severely limited performance.
  It would, however, be a feasible option if you simply couldn't afford to spend any money at all but still needed to access your iMac.

-off-topic: after several months of compulsively trying to get my 2011 iMac to work again, I ended up, by chance, buying a 2014 iMac with a broken (but working) retina display, which I intended to repair and sell for a profit. Having disassembled and reassembled my old iMac so many times had the perk of allowing me to take these things apart with my eyes closed, now. It cost me only slightly more than any MXM GPU card I had bought before to replace the 6970 and, ironically, I ended up keeping this system for me. This whole process of trying to bring my then beloved 2011 iMac to life just wore me down to a point where I simply considered the resources invested (wasted) in it to be higher than the loss of an item that cost me over £2,000 less than 4 years before.

Again: these are just my thoughts based purely on personal experience and may not be 100% accurate. Others may have different conclusions based on their success (or lack of) stories. Feel free to correct me or offer any suggestions on where I may be wrong.

Good luck and lots of patience!

 

[T'hain Esh Kelch]

You also have the option of doing a reflow. Mine is still going strong 7 weeks after I did it to mine, as described above, no matter what I throw at it. Of course, it can die again any day, but at least it only cost me two hours of work to do so.

 

[Lost Heaven]

You also have the option of doing a reflow. Mine is still going strong 7 weeks after I did it to mine, as described above, no matter what I throw at it. Of course, it can die again any day, but at least it only cost me two hours of work to do so.

Spot on, I knew I'd miss something. I'll edit the post and mention your suggestion for the sake of accuracy.

 

[MrBat]

• if you're willing to part with or don't need certain functionalities, such as the boot screen and native brightness control, you can buy an MXM GPU pulled from a non-Apple system. You'll have to rely on reports by other users who successfully took this route to determine which cards are compatible. Not only will you have to search for a certain model, you'll also need to find specific brands and BIOS versions. Any mismatch in those combinations will make it unusable in your iMac. As a consequence, finding one of these cards takes a considerable amount of time.
  You may have to perform physical modifications on your heatsink as some cards won't fit in it as the 6970 does.
  This does have the benefit of giving you a performance boost, provided the card you buy is more powerful than the 6970.
  I have to reinforce that this is only a valid option if you are positive you are happy to part with the boot screen and brightness control. From my experience, depending on which card you get, your system will also likely be less stable than it was with the stock GPU, with the occasional crash, freeze or boot into a white or black screen.
  If you use BootCamp, it may also not work with Windows.
  Having taken this route, I was surprised to find out that I couldn't cope with the loss of brightness. Apparently, some people are less sensitive to this than others. No brightness control app that I've tried managed to have the same effect that the native one did with the stock GPU, simply because they don't control the brightness at all: they simply apply some sort of filter that tints the screen darker or lighter. Actual brightness never really changes. This is easy to observe on a dark room. I found that this makes the image dull and couldn't cope with it. You may not be as sensitive to this.

Again: these are just my thoughts based purely on personal experience and may not be 100% accurate. Others may have different conclusions based on their success (or lack of) stories. Feel free to correct me or offer any suggestions on where I may be wrong.

Good luck and lots of patience!

Let's say I decide to "upgrade" the iMac 2011 with a non apple GPU, but stick with Bootcamp only on Windows 10.

• Will the brightness adjustment work in Windows 10, even if only manually?
• I drive 2 additional displays, as seen below. Will both work after an upgrade?
• Is there a list available of what are the best compatible cards available for this?

Any kind of info is more than welcome.

 

[Lost Heaven]

Let's say I decide to "upgrade" the iMac 2011 with a non apple GPU, but stick with Bootcamp only on Windows 10.
Will the brightness adjustment work in Windows 10, even if only manually?

It's impossible to give a definite answer to your questions because different GPUs may yield different results. In my experience, I don't believe brightness control ever worked in Windows 10 either, although I'm not 100% positive (it has been almost 1 year since I gave up on this enterprise). Same with adaptive brightness.

I drive 2 additional displays, as seen below. Will both work after an upgrade?

While I only tested it with a TV connected via a Mini-DisplayPort to HDMI cable (I think that's what it was), it did work. In fact, it's the only way you can access your Mac, either in macOS or Windows, when booting it for the first time after installing the GPU, other than Screen Sharing or Remote Desktop. If you don't have these enabled beforehand, you'll need an external display to install drivers for the card and get the internal display to work.
I can't comment on display arrangements or extended desktops or whatever they're called, but I'm convinced they worked as well. Again, it depends on your card and its drivers.
Finally and if it doesn't work, with Windows you have, at least, the possibility to get modified drivers or modify them yourself (also needed, sometimes).

Is there a list available of what are the best compatible cards available for this?

Yes, but it's not really organised: this thread
It really is, as far as I'm concerned, the best resource available on the topic of upgrading an iMac's GPU. While there are a couple of other threads on other forums with some valuable information, here is where I found the most posts by users (pioneers?) who went ahead and replaced their cards with others and reported their stories.

 

[MrBat]

It's impossible to give a definite answer to your questions because different GPUs may yield different results. In my experience, I don't believe brightness control ever worked in Windows 10 either, although I'm not 100% positive (it has been almost 1 year since I gave up on this enterprise). Same with adaptive brightness.


While I only tested it with a TV connected via a Mini-DisplayPort to HDMI cable (I think that's what it was), it did work. In fact, it's the only way you can access your Mac, either in macOS or Windows, when booting it for the first time after installing the GPU, other than Screen Sharing or Remote Desktop. If you don't have these enabled beforehand, you'll need an external display to install drivers for the card and get the internal display to work.
I can't comment on display arrangements or extended desktops or whatever they're called, but I'm convinced they worked as well. Again, it depends on your card and its drivers.
Finally and if it doesn't work, with Windows you have, at least, the possibility to get modified drivers or modify them yourself (also needed, sometimes).


Yes, but it's not really organised: this thread
It really is, as far as I'm concerned, the best resource available on the topic of upgrading an iMac's GPU. While there are a couple of other threads on other forums with some valuable information, here is where I found the most posts by users (pioneers?) who went ahead and replaced their cards with others and reported their stories.

Thanks for the clarification. Brightness adjustment is kind of a dealbreaker for me, sadly.

I've sent an email to macvidcards inquiring about possible solutions, although it seems they only deal with Mac Pros.

Although I truly love my top of the line iMac 27" 2011, I'm beginning to seriously think on selling the iMac for parts and build a hackingtosh. At last as hackingtosh, you've got to boot in Windows with no trouble and can always find a time consuming way to make macOS work.

In overall, after the guarantee expires, the apple road is a rather painful one with much bitterness, headaches and crazy money to sink.

--

After getting the iMac checked, there's no way I'm going to throw away ~700 EUR to Apple for a 6 years old GPU replacement which may fail in about 1-2 years, or less.

Paying top dollar for a "new" yet heavily outdated 27" 5K iMac is not an option I feel inclined to go for, specially after this experience and having in mind that the latest iMacs are just a laptop with a big screen.

I like future proof things or said differently, things I can get repaired and/or upgraded in a cost effective manner.

Alas, I'm making the full jump to PC.

I ordered a Ncase M1 to be fit with an AMD Ryzen and a high end GPU I still have to make my mind about.

Amusingly enough, I wanted to get my hands on a 2nd hand 27" Apple Led Cinema Display, so I could drive it with Display Port + USB for adjustments. Unfortunately, these displays seem to be really hard to get by and the 27" Thunderbolt Cinema Display won't work with PC. This really upsets me, for I do hate cable clutter, with passion.

Dell Ultrasharp will have to do + webcam + speakers. SAD!

All in all, the Apple ride has been lovely for many years. Apple long stopped manufacturing appealing computers for folks like me. RIP Steve.