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

[Cordonblu]

I finally got my K4100M card in my 2011 27" iMac working. First card was not correct. The second card I got which was a Dell turned out to be bad. Third time was a charm and the replacement card worked the first time.

View attachment 939100

Here are the lessons learned from this experience:

1. Do not use HP versions of the K4100M card. Something is different about them and they don't work.
2. The Dell version of the K4100M cards work.
3. I learned how to completely disassemble this iMac having taken it apart and reassembled it about 18-22 times in total.
4. Just put a little pile of K5 compound on the tall square areas, just enough to fill the gaps.
5. Don't do this work when you're exhausted - too many opportunities to make mistakes which causes more problems.
6. On the bootable USB image, the scp command - that is to be run from your local machine, not the target iMac that you ssh'd into. Run it in a terminal on your local machine.
7. This took about three days to do, don't take up kitchen space if you don't want your wife to be pissed off at you.
8. I love my iFixit toolkit. It came in so handy for this job.
9. The Linux USB image is the way to go. Super convenient and pretty easy if you're familiar with ssh and such.
10. Did I mention to stay away from HP versions of the K4100M? Steer clear of them, they don't work.

Thanks to this thread and all who helped me through this process. I really appreciate it. I think I had this thread bookmarked for well over a year waiting for a card that worked better than the existing cards did. Finally the K4100M came to the working list and I was all over it. Thanks again to everyone and @nikey22 for the firmware that allowed this to happen!

Special thanks to @highvoltage12v for answering so many questions in this thread along with all the others that replied. You all rock!

Good job!
But I can confirm that atleast my HP K4100M is working without problems maybe it was pure luck but it's been working since Tuesday that I did fix the clock issue. For scp as cli is not that intuitive you can use winscp in windows or cyberduck in mac to remote in the iMac via SSH and just grab the file, these are just SSH/SCP/SFTP gui programs so they are fully compatible.

 

[Ausdauersportler]

After more testing, I've noticed that some small glitching in the form of horizontal lines appear and disappear at the right side of the screen for short periods since bootscreen, flashing back to Nick [D]vB Kepler beta 3 resolves this issue for me, so I could discard the possibility of a hardware problem.

The card is not running hot (GPU Heatsink is 40 ºC) and the area surrounding the card is cool, this could be because of my inusual setup? (21.5" 2010 + 780m). Is there a problem if I keep running this new firmware? I don't mind seeing some glitching if the backlight could be saved from frying.

PD: if someone could please lead me to some ROM hacking learning resources, it would be much appreciated, I'm very interested in this topic and have some spare time right now.

From the first post:

1. There are two type and sizes of cards: Smaller MXM-A cards and bigger MXM-B cards running stable only in the 27" models. While all cards will function in a 21.5" model, they are unstable due to their high power draw. @highvoltage12vtested a 770M here and had frequent Kernel Panics in macOS and BSoD's in Windows. Do not try it!

 

[passatgt]

** NVIDIA GeForce GTX780M ROM **

Genuine Native Boot Screen & Brightness Control

"this is insanely great!"
-Steve Jobs​

There are many members here that have this card now and have been using it with & without Opencore. The previous rom iterations did not initialize the “built-in” iMac LCD screen but instead spoofed it to use the Cinema Display as the internal screen which rendered brightness control non-functional, and forced the use of a bootloader to add the feature back via a kernel extension.

I have put together a ROM for the NVIDIA GeForce GTX780M which will allow:

• Genuine native brightness control
• Genuine ‘gray’ early-boot screen (stage 1 & 2 progress bar)
• Genuine macOS bootloader ready

This ROM does not require a 3rd party bootloader like OpenCore.

ROM testing has already been underway for the past few weeks by @Ausdauersportler and @highvoltage12v.

There is an overclock present on the GTX780M from the base rom. I would suggest you to use a 3-pipe heatsink for this GPU. Apply proper thermal pads and appropriate heat dissipating grease like K5pro to the areas that are in contact with the heat sink. Keep mac fans up and running to achieve better control of cooling as well.

As with the K4100M, you will need to use a brightness kext mod to obtain the proper range of brightness in macOS. There will be a separate instruction for Windows 10 users to adjust the RMBrightness scaling accordingly.


Important Links:
USB Flashing for SSH @xanderon method <link>
@Curtis Gross – walkthrough video <link>
Heat Sink MOD to grind down the edges <link>
Heat Sink mounting @tgaillar <link>
Kexts for sleep/iGPU (Mojave/Catalina) <link>



More GPU Roms to come... Enjoy!

Thanks for this! I installed in on my 780M 2011 27", but even on max brightness, the screen is a lot dimmer compared what it was previously. Any ideas about this?

 

[Ausdauersportler]

Thanks for this! I installed in on my 780M 2011 27", but even on max brightness, the screen is a lot dimmer compared what it was previously. Any ideas about this?

Read the announcement @nikey22 made word by word You will find it! And before you had no control at all and so the absolute max. of the backlight burning at 100%. Which is insanely bright. Even Apple does not allow to burn in a picture .

 

[passatgt]

Read the announcement @nikey22 made word by word You will find it!

Sorry, i thought that only applied to k4100m, i'm stupid

 

[ssaman]

From the first post:

1. There are two type and sizes of cards: Smaller MXM-A cards and bigger MXM-B cards running stable only in the 27" models. While all cards will function in a 21.5" model, they are unstable due to their high power draw. @highvoltage12vtested a 770M here and had frequent Kernel Panics in macOS and BSoD's in Windows. Do not try it!

It was clear to me from the very beginning that my setup is unconventional, but the card actually ran stable with the prior Kepler Beta3 firmware, and it is under continuous use since it became my main machine back in February, it ran stable asides the lack of brightness control or the chime screen. Even with this new patch I don't get any kernel panics or errors on the OS X Console, it runs like it always did, it's just that I'm getting this short horizontal lines.

I don't get to see those lines when rolling back to the prior firmware, making me think that there's some tweaking that could be made for remediating this, and since my setup is unconventional, I'm willing to do this tweaking by myself. If someone has a lead of what could I do, it would be much appreciated.

 

[Ausdauersportler]

Sorry, i thought that only applied to k4100m, i'm stupid

No, you just missed it. As we both know reading docs is for chicken...

 

[passatgt]

One issue i noticed is banding and gradient problems. For example on this screenshot you can see some dark bars at the bottom, its not fully white:

Theres significant banding when launchpad is visible too:

 

[Allistah]

Looking at the first post you may find out that Target Display Mode works only with High Sierra. Using Mojave or Catalina ends up in the mess you just described. Apple pulled off the support for TDisplayM from the recent MacOS versions and nobody found a way to bring it back until, now.

Please, please read the posts #1 first and post later

I booted into a clean install of High Sierra and while the brightness controls returned in Target Display Mode, exiting by pressing CMD-F2 a second time still did not exit Target Display Mode. I still had to unplug the cable to turn off the feature.

In Mojave, I also noticed that when you download a file, the graphic that moves/flies down to the downloads area on the dock, it seems to move in a stuttering pattern so to speak. Not sure if that happens in HS or Catalina or not. I haven't checked that out.

 

[highvoltage12v]

I booted into a clean install of High Sierra and while the brightness controls returned in Target Display Mode, exiting by pressing CMD-F2 a second time still did not exit Target Display Mode. I still had to unplug the cable to turn off the feature.

Yes for Mojave and Catalina TDM has never worked right. Sometimes the computer will even kernel panic 10 minutes after. I don't know what files in Mac OS control TDM, but if I did I'm sure they can be used from High Sierra.

 

[highvoltage12v]

Sorry, i thought that only applied to k4100m, i'm stupid

I need to add it to the post and page 1, sorry.

 

[highvoltage12v]

One issue i noticed is banding and gradient problems. For example on this screenshot you can see some dark bars at the bottom, its not fully white:

View attachment 939234


Theres significant banding when launchpad is visible too:

View attachment 939235

Do you only notice the issue in High Sierra?

 

[passatgt]

Do you only notice the issue in High Sierra?

I'm on Catalina 10.15.2

 

[Curtis Gross]

** NVIDIA GeForce GTX780M ROM **

Genuine Native Boot Screen & Brightness Control

"this is insanely great!"
-Steve Jobs​

There are many members here that have this card now and have been using it with & without Opencore. The previous rom iterations did not initialize the “built-in” iMac LCD screen but instead spoofed it to use the Cinema Display as the internal screen which rendered brightness control non-functional, and forced the use of a bootloader to add the feature back via a kernel extension.

I have put together a ROM for the NVIDIA GeForce GTX780M which will allow:

• Genuine native brightness control
• Genuine ‘gray’ early-boot screen (stage 1 & 2 progress bar)
• Genuine macOS bootloader ready

This ROM does not require a 3rd party bootloader like OpenCore.

ROM testing has already been underway for the past few weeks by @Ausdauersportler and @highvoltage12v.

There is an overclock present on the GTX780M from the base rom. I would suggest you to use a 3-pipe heatsink for this GPU. Apply proper thermal pads and appropriate heat dissipating grease like K5pro to the areas that are in contact with the heat sink. Keep mac fans up and running to achieve better control of cooling as well.

As with the K4100M, you will need to use a brightness kext mod to obtain the proper range of brightness in macOS. There will be a separate instruction for Windows 10 users to adjust the RMBrightness scaling accordingly.


Important Links:
USB Flashing for SSH @xanderon method <link>
@Curtis Gross – walkthrough video <link>
Heat Sink MOD to grind down the edges <link>
Heat Sink mounting @tgaillar <link>
Kexts for sleep/iGPU (Mojave/Catalina) <link>



More GPU Roms to come... Enjoy!

Nice! Don't tempt me!
Also - looks like your link to my video is going to Xanderon's post. Just a FYI.

 

[Curtis Gross]

Just download mac fan control and set a custom limit for the hdd sensor, this is the setup that I run:
View attachment 938899

Note that my settings are based in the safety data from WD.
The original HDD had a custom fw/sensors from apple that reported the info to the system so the new ssd/hdd doesn't have it, don't buy any new sensor-cable just use the mac fan control.

I have been digging into this a bit (fans ramping for hard drive replacement) and simply adding a y-splitting sata cable actually fixes the fan ramping issues as well.
https://www.ifixit.com/Answers/View/51575/HDD+Temperature+sensor+gone+in+2011+iMac#answer63228
So if you want to remove the software solution, just add a y-splitter for ~$7 and you are good 2 go. Also a cheaper way to get power to more devices if needed.

 

[Curtis Gross]

A quick question - could you please confirm that 1mm thermo pads are ok for K2100m (or other recommended cards)? In the location I live K5 is very difficult to source unfortunately...

Not that I would recommend this.. but I have a k2100m that is running without any thermal pads on it and have been doing that for a few months. Just make sure that your GPU die is properly covered in thermal paste. Or buy the 1mm pads and double up on them if you need to get more room covered under the sink.

 

[Cordonblu]

I have been digging into this a bit (fans ramping for hard drive replacement) and simply adding a y-splitting sata cable actually fixes the fan ramping issues as well.
https://www.ifixit.com/Answers/View/51575/HDD+Temperature+sensor+gone+in+2011+iMac#answer63228
So if you want to remove the software solution, just add a y-splitter for ~$7 and you are good 2 go. Also a cheaper way to get power to more devices if needed.

You still need the mac fan control to keep cool the gpu as the ODD fan isn't very noisy and its a good idea to manually ramp up the rpm dynamically ( based on sensor temperature ) to 100% so avoid cooking the gpu.
I like to keep the gpu die under 60 just to be safe as these gpus aren't cheap.

 

[Ausdauersportler]

Just download mac fan control and set a custom limit for the hdd sensor, this is the setup that I run:
View attachment 938899

Note that my settings are based in the safety data from WD.
The original HDD had a custom fw/sensors from apple that reported the info to the system so the new ssd/hdd doesn't have it, don't buy any new sensor-cable just use the mac fan control.

Take a look here, has been discussed on this thread...

 

[r6mile]

I booted into a clean install of High Sierra and while the brightness controls returned in Target Display Mode, exiting by pressing CMD-F2 a second time still did not exit Target Display Mode. I still had to unplug the cable to turn off the feature.

In Mojave, I also noticed that when you download a file, the graphic that moves/flies down to the downloads area on the dock, it seems to move in a stuttering pattern so to speak. Not sure if that happens in HS or Catalina or not. I haven't checked that out.

As I mentioned before, I had the same issues with TDM under High Sierra with a K2100M. I don't think it's an issue with the OS necessarily, it must be to do with the new flashed Quadro card. It wasn't a huge deal, having to unplug the cable, but clearly functionality for TDM is not 100% even with these cards. It mighty be worth adding this to the main page, if others are also experiencing these symptoms.

 

[passatgt]

Do you only notice the issue in High Sierra?

I think the screen is running at 16 bit, even though system report says 24bit.

 

[Tom.Tom]

no, I did not flash the BIOS. my original graphics card burned out. I bought a msi gtx 770 from a laptop, there is a gong on imac, I understand that the system has booted (if you press the keyboard, system sounds are heard) but the screen is black!

Read the first post - you need to flash the 770 rom to have it working with iMac. All information about this process is there (and in the linked posts).

 

[Tuscon]

After replacing my failed graphics card with an Nvidia 765m everything works as expected. Brightness I can live with until hopefully someone creates a working rom. Just after I use the mac for a while and temp stays below 60 my wifi quits working. Is this know behavior?

Thanks for any response.

iMac 27 late 2009 High Sierra

 

[josgar082]

Hi. I have a iMac 2011 27" i7 3.4ghz which has an ATI Radeon HD 6970M 1GB, I decided to change it for the NVIDIA GTX 770M 3GB, which was my surprise, when I installed it it didn't work, in the board only the first two leds were lit, and even though my computer emitted the classic sound of boot on a Mac, the screen stayed black and after a few seconds the fans accelerated to the maximum, I checked that everything was correctly connected, it was, this time I turn it on and it doesn't start, it tries to turn on and after a few seconds it turns off, it only turns on a led. I have realized that there are two types of cards, some green and others blue, technically I don't know what differentiates one from the other to be compatible or not, it would be good to explain these differences in the same card to avoid confusion and not happen to someone else. I have talked to the store and they tell me that the card is good, that they tested it before sending it, that it is only compatible with Dell Alienware but not for iMac, when I bought it totally convinced of its compatibility because of the amount of videos I have seen installing this card (which I mean are blue, mine is green) and based also on this forum. Don't let this happen to you, don't trust only the make and model, there are more aspects that depend on compatibility.

If anyone knows what else might be causing the lack of compatibility and has a solution, please let me know. On the other hand, the store will help me, they will change it if they have a compatible one or they will give me my money back, I bought it through Amazon. Thank you very much.

 

[highvoltage12v]

How to Enable Brightness Control then fix Brightness Levels on the K4100M/780M/k2100M/K1100M. For some Background information, I’m using the k4100, my driver version is 416.34-notebook-win10-64bit-international-whql. Different drivers may not work.

First go Post #6,036 and Download NVIDIA Brightness enable.zip, run the DispRegEdit.exe file this will direct you to the correct area of Regedit to add/change values.

1. First add the DWord For “EnableControlBrightness” right click on some blank area of the window and add a new Dword the value name is “EnableControlBrightness”. Then right click on the new Dword and click “modify” The “Base” value should be Hexadecimal and value data should be “1”.

I suggest you reboot Windows, you should have the brightness slider in Settings (not Control Panel) and it should work. But 100% brightness will be about 60%, time to fix this.

2. Open DispRegEdit.exe this time look for the Value “RMBrightnessControlFlags” we need to right click on it and click “modify” then change the value from “320” to “400”. Then reboot again, this should fix Brightness values For @Nick [D]vB and @nikey22 ROMS.

 

[Ausdauersportler]

Hi. I have a iMac 2011 27" i7 3.4ghz which has an ATI Radeon HD 6970M 1GB, I decided to change it for the NVIDIA GTX 770M 3GB, which was my surprise, when I installed it it didn't work, in the board only the first two leds were lit, and even though my computer emitted the classic sound of boot on a Mac, the screen stayed black and after a few seconds the fans accelerated to the maximum, I checked that everything was correctly connected, it was, this time I turn it on and it doesn't start, it tries to turn on and after a few seconds it turns off, it only turns on a led. I have realized that there are two types of cards, some green and others blue, technically I don't know what differentiates one from the other to be compatible or not, it would be good to explain these differences in the same card to avoid confusion and not happen to someone else. I have talked to the store and they tell me that the card is good, that they tested it before sending it, that it is only compatible with Dell Alienware but not for iMac, when I bought it totally convinced of its compatibility because of the amount of videos I have seen installing this card (which I mean are blue, mine is green) and based also on this forum. Don't let this happen to you, don't trust only the make and model, there are more aspects that depend on compatibility.

If anyone knows what else might be causing the lack of compatibility and has a solution, please let me know. On the other hand, the store will help me, they will change it if they have a compatible one or they will give me my money back, I bought it through Amazon. Thank you very much.

Start reading at post #1 of this thread, you will be surprised. This is the end of the book, not the beginning.