General Questions (Last Updated 06/10/2020)
We are still aggregating GPU benchmarks! You can help by running UNIGINE VALLEY on your iMac at 1080P MEDIUM and submitting the results HERE!
You can also VIEW the results in real time HERE!
A PDF Chart summarizing this info has been added to this post - see attachments.
Q: What cards are working? Is there a list?
A: Yes - specifics are below, but current working cards are:
- NVIDIA Quadro K2100M +
- NVIDIA Quadro K1100M +
- NVIDIA Quadro K2000M *
- NVIDIA Quadro K1000M *
- NVIDIA GTX 780M ++
- NVIDIA GTX 770M *
- NVIDIA GTX 765M *
- AMD Radeon WX7100 **
- AMD Radeon WX4170 **
- AMD Radeon WX4130 **
- NVIDIA GTX 860M ***
- NVIDIA Quadro K610M ****
- NVIDIA Quadro K4100M ****
While other cards may work, these are currently the recommended cards. If you would like to use a different card, consider yourself in unknown territory, and of course, let us know if it works!
The modified VBIOS version made by
@Nick [D]vB require an Intel i3 CPU or better. There is currently no way to make the features of these VBIOS working on Core 2 Duo systems (late 2009).
+ These cards have modded VBIOS by
@Nick [D]vB that currently enable boot screens on your iMac. Using
OpenCore these cards offer right now
native brightness control, target display mode, UEFI Windows 10, and more! To enable backlight in UEFI Windows 10, see
this post by
@internetzel.
* These cards have modded VBIOS by
@Nick [D]vB that currently enable boot screens on your iMac, better performance, and BootCamp support.
There is a small delay between the chime (POST) and the initialization of the actual boot screen on the current NVIDIA modded VBIOS. Most of the time (such as a quick reboot in macOS) the system boots too quickly for the EFI portion of the VBIOS to initialize, making it appear that you may not have a "boot screen." All is working as intended if you can hold the "Option" key at startup and get a boot picker.
++ This card has a modded VBIOS by
@Nick [D]vB that currently enable boot screens on your iMac, better performance, and BootCamp support. According to this
post from April 2020
@Nick [D]vB is working on a new VBIOS version offering native brightness control, target display mode, and more.
** These cards are much more modern, but are difficult to source. With custom VBIOS and OpenCore, these are very compatible and offer
native brightness control, boot screens, UEFI Windows 10, and much more modern capabilities and future-proofing than the NVIDIA cards, if you can find one. See "AMD" below for more info.
*** The GTX 860M does work, but does not have a custom VBIOS like the others. Additionally, some cards will still need to be flashed with a new VBIOS for internal display functionality. Multiple GPU cores were used on the GTX 860M in manufacturing, but only Kepler based cards work in iMacs.
**** Like the GTX 860M, the Quadro K610M works with the correct VBIOS. Originally
posted and tested without a custom VBIOS by
@jowaju, they can be found for as low as $9 US.
@nikey22 published a custom
VBIOS based on the work of
@Nick [D]vB with boot screen and more using the same OpenCore setup as described with the Quadro K1100M and K2100M. The youngest kid on the block is the K4100M. You will find a
vBIOS also by
@nikey22 and a comment about the experimental status in the linked post. Preparation of the heat sink will be the same as for the 780M card, it shares size and layout.
Q: What new issues will I have after swapping my card with a PC MXM card?
A: The biggest issues we have are:
- The loss of EFI boot screen
- The loss of Backlight control
- You can only connect one external monitor to 27" iMacs
- The loss of Target Disk Mode
- The loss of Target Display Mode
- The loss of running the built-in Apple hardware test
- The loss of temperature sensors on the new GPU
1. Boot screens are now available on all listed cards except the GTX 860M and the K610M using Custom VBIOS and/or OpenCore.
@Nick [D]vB's VBIOS enabling boot screens on GTX 765M/770M/780M are available
here.
@Nick [D]vB's VBIOS enabling boot screens on Quadro K1000M/K2000M/K1100M/K2100M available
here.
See the "AMD" section below for AMD info. You may use the OpenCore booter to add a boot screen feature to every card - even the Nvidia and AMD cards not listed here or known to have no vBIOS support to show the apple boot picker.
2. Native brightness control is available for the Quadro K1100M and K2100M as well as the AMD cards using a combination of custom VBIOS and OpenCore. See
this post for information about using OpenCore. A guide to using the provided OpenCore disk image by
@Nick [D]vB has been written by
@herrdude on
THIS POST.
For other cards, brightness control may be added in the future. Be aware that without brightness control, the iMac display runs at full brightness by default. For higher powered cards and 27" models, this can generate a lot of heat.
If you would like to "dim" your display using color dimming, many have used the app
Brightness Slider, which is available on the App Store for free.
You can also use
this app, which works better than most apps in the App Store, because it will dim the colors on the whole screen and it will display the built-in OSD, just like native brightness control.
Additionally, hardware level modifications using a DyingLight module or a Raspberry Pi have been used for brightness control.
This software written by
@passatgt can be run on a Pi for backlight control.
Last, but not least: User
@Lottosmp came up with a
solution based on the former engineering.
3. Despite having
2 miniDisplayPort outputs, the 27" 2011 iMac will only output to one external display. There is currently no fix or workaround for this.
4. Target Disk Mode is available on all cards with available custom VBIOS.
5. Target Display Mode is available on the K1100M, K2100M, WX4170, and WX7100 when using both custom VBIOS and OpenCore. Target Display Mode is *only* stable under High Sierra and should not be used in later OS's.
6. AHT: There is currently no fix for running the internal service diagnostics. You may search the net for the ASD (Apple Service Diagnostic) package instead. For each system there is a different package. Download and install on SD card or DVD gives you back the full functionality. A working download link may be hard to find. It is not open source.
7. GPU temperature monitoring is available on the K1100M, K2100M, WX4170, and WX7100 when using both custom VBIOS and OpenCore. A modified version of FakeSMC and GPUSensors is included with the OpenCore bundle to allow monitoring of GPU temps.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Q: Is this easy? I need a quick fix for my iMac!
A: Not necessarily. This "fix" is more of a "mod" to revive our iMacs. Depending on your scenario, it requires full iMac disassembly, knowledge of VBIOS flashing, dremel tools, heatsink modification, careful handling of logic board components, etc. With the used/grey market for many of these cards, other issues may pop up as well.
Please be cautioned before undertaking this process.
Q: My system boots up, but I don't have internal display, any display, or my GPU is not recognized correctly. What do I do?
A: Your MXM card is likely running an incompatible VBIOS and will need to be flashed with the correct one. This can be done from within Windows or Linux using NVFlash, or with a CH341a programmer. Common cards and their VBIOS are:
Q: Flash VBIOS? How do I do that?
A: VBIOS can be flashed in one of two ways: Either directly with a CH341a clip programmer or with the "NVFLASH" software in Windows or Linux.
THIS POST helps describe the flashing process. Others have found
THIS POST useful. User
@xanderon created a pre-made USB that can flash Nvidia cards in the iMac with Linux over SSH. Many have found this the easiest method. There is an
add-on to flash AMD cards using this method, too. Additionally, user
@jowaju created
a simple Installer package that can be run on macOS Sierra (10.12) and higher that creates a 15GB Windows 7 Bootcamp partition with all the needed tools.
Q: OK, so I need to use the NVIDIA web drivers, right?
A: No - all cards outlined in this guide use the included NVIDIA drivers in macOS. No additional GPU drivers are needed.
Q: Why aren’t you using Maxwell or Pascal cards in the iMac?
A: A lot of people here have tested Maxwell cards with their 2011 iMacs, and have had various issues from no internal display, no backlight on internal display and the card not hitting boost. Additionally, macOS Mojave (10.14) deprecated support for the NVIDIA Web Drivers which allowed the use of Maxwell and Pascal cards. For now, Kepler GPUs and the experimental Radeon cards seem to be our path forward.
Q: Can I use a 4K display with these cards? The original card doesn't support 4K.
A: Yes! So far, the K1100M & GTX 770M have been tested firsthand and successfully provide 4K@60Hz output via mDP to DP adapter on a 4K display. Others should work just as well.
2009-2011 27” iMac MXM card upgrade Q/A
Q: What MXM cards are known working?
A: Unlike the 21.5" iMacs, the 27" models do not have any restrictions due to power draw. All GPUs listed at the top of this post work in the 27" models. The NVIDIA MXM-B cards require heatsink modifications, but the MXM-A cards and AMD cards do not. See below for info.
Q: Are there any internal modifications needed for an MXM-B swap?
A: There are 2 mods needed to make the MXM-B card fit. First you must grind down your heatsink in the area where two large coils sit, this way the card will sit flush with the heatsink. Second, you must drill out or tap out the rivets on Dell’s X-Clamp or grind away Apple’s X-Clamp so no capacitors or components touch the X-Clamp or sit under it. Skipping this step can fry or damage your card. Alternatively, user
@tgaillar was able to use different screws and washers to avoid any drilling - see
here.
If you have a
2 pipe heatsink that came with the lower end GPUs on these iMacs and want to use an MXM-B Card, you'll have to buy a
3 pipe heatsink to cool it properly. You can get these on eBay.
Q: Are there any internal modifications needed for an MXM-A swap?
A: For an MXM-A swap (the shorter/less power draw cards) there are no modifications that are needed for the heatsink on both the 21.5" and 27" model iMacs. The X-clamp still needs be removed from the back of the card and have the screw posts drilled out (
or screws swapped) in order to fit the heatsink's screws. If you've cleaned your heatsink, be sure to re-apply thermal pads around the GPU VRAM to prevent contact with the bare metal of the heatsink.
2010-2011 iMac 21.5" iMac MXM card upgrade Q/A
Q: What MXM card(s) are known working?
A: Currently, the NVIDIA Quadro K1000M, K1100M, K2000M, and K2100M are the preferred MXM card's to swap due to space issues and low power draw of these cards. While the GTX series cards recommended above will function in a 21.5" model, they are unstable due to their high power draw.
@highvoltage12v tested a 770M
here and had frequent Kernel Panics in macOS and BSoD's in Windows.
Q: Are there any internal modifications needed for an MXM-A swap?
A: For an MXM-A swap (the shorter/less power draw cards) there are no modifications that are needed for the heatsink on both the 21.5" and 27" model iMacs. The X-clamp still needs be removed from the back of the card and have the screw posts drilled out, tapped out,
or screws replaced in order to fit the heatsink's screws. If you've cleaned your heatsink, be sure to re-apply thermal pads around the GPU VRAM to prevent contact with the bare metal of the heatsink.
Q: What paste is recommended to cover the VRAM/Components on the MXM card like Apple’s design?
A: For the GPU Die any thermal Paste like Thermal Grizzly’s Kryonaut paste is good for the Die. For onboard components, many recommend using K5 Pro Viscous paste instead of thermal pads, due to the unevenness of the heatsink, it’s also similar to Apple’s original Design:
https://www.amazon.com/gp/product/B00K04D3UK/
https://www.computer-systems.gr/en/product-category/consumables
Installing macOS on your upgraded iMac
With the addition of our newer GPU, Metal is natively supported allowing for installation of macOS Mojave and Catalina with full graphics acceleration. Until May 2020 the installation of
High Sierra did not need any changes, but the most recent patch set delivered by Apple makes it necessary to install a modified
kernel extension to avoid a black internal screen after reboot. It is basically the same kind of
patch, needed for Catalina 10.15.4 and newer, probably Mojave will need it, too.
(I cannot currently confirm this issue. Having an external display connected seems to hide it.)
See additional info below:
Note: If using OpenCore, some of the below fixes are included in the OpenCore bundle! Please read
the OpenCore post for more info. If you have previously modified your system for the below fixes, they will need to be removed to avoid conflict with the OpenCore injection.
Installing macOS Sierra
Some users might see a black screen on macOS 10.12 "Sierra" after swapping to an NVIDIA card.
Link to information on getting macOS Sierra running with non-apple Nvidia graphics cards:
https://forums.macrumors.com/threads/2011-imac-graphics-card-upgrade.1596614/page-25#post-24105622
Installing macOS Mojave
Since you will have a Mojave compatible GPU, you could run the newest macOS without any serious issues. The recommended method is to have High Sierra as your primary OS and install Mojave alongside on a separate partition. So if anything goes wrong, you can still boot back into High Sierra to fix issues. You could preinstall Mojave before changing your GPU. Use dosdude1's Mojave patcher to do the install:
http://dosdude1.com/mojave/
Important: while running the Post Install tool, make sure you deselect the Legacy Video Card patch option (since you will using a new, compatible metal graphics card).
Installing macOS Catalina
The process for Catalina is similar to Mojave, above. Similarly to Mojave, you could preinstall Mojave before changing your GPU. Use dosdude1's Catalina patcher to do the install:
http://dosdude1.com/catalina/
Important: Post-install patching has changed since Mojave. Patching is now automated if your SMBIOS is detected to be an unsupported machine. Currently, only the 2011 iMacs have the "Legacy Video Card Patch" disabled by default. You will want to avoid this patch (since you will using a new, compatible metal graphics card) and will need to modify a plist file if you are using a 2009/2010 iMac with a Metal compatible video card. While building the patcher, you can go to the "Options" menu and de-select "Auto-Apply Post-Install Patches" to avoid this. See next question to manually fix this issue.
10.15.4 has been causing "black screen" issues for many folks. This is caused by a lack of kext initialization due to a lacking board-id in the AppleGraphicsControl.kext. A patched kext and a further explaination can be found
HERE, thanks to
@highvoltage12v.
Q: After installing Catalina on my Late 2009/2010 iMac my animations are broken/choppy, the Dock is grey and the menu bar isn't translucent. How do I fix this?
A: The dosude1 installer unfortunately automatically executes the "Legacy Video Card Patch" leaving Late 09/2010 MXM swapped users with broken/choppy animations. If you did install Catalina and would like to manually reinstall the stock Kexts and Frameworks, a guide has been written by
@highvoltage12v here to manually overwrite the patched files with stock files.
"Unsupported" OS Fixes
Q: Sleep is broken in Mojave, how do I fix this?
A: This is caused by the removal of the SandyBridge kexts in Mojave. Although we aren't using the iGPU, these kexts are still needed for proper sleep functionality. A zip file is attached with the proper kexts to restore sleep in Mojave. Inside the unzipped folder contains the App Kext Utility and the necessary SandyBridge kexts that need to be installed. Right click to open Kext Utility, then immediately quit. Select all the files inside the folder and drag them on top of Kext Utility and allow them to install.
Q: Sleep is broken in Catalina, how do I fix this
?
A: Similar to the above issue in Mojave, the SandyBridge kexts are missing in Catalina. Installing them like Mojave fixes sleep, but causes extended boot times.
@highvoltage12v has provided a patched IOSurface.kext containing the SandyBridge kexts in
THIS POST which can be installed using the same method as above to resolve both issues.
Q: I want to help and experiment, what can I do?
A: First, read the full thread. Staying on top of the progress here is key! Currently, backlight mods in VBIOS are being researched as well as boot screens and alternate video card solutions.
AMD:
See notes above. These cards are much more modern and offer a greater future-proofing than the NVIDIA cards but can be tough to source. Using a combination of custom VBIOS and OpenCore, these cards to have both native brightness control and boot screens. They also allow for Sidecar, H.264, and huge HEVC decode/encode gains in production. At the time of writing this, performance is hindered by macOS drivers, VBIOS clocks, sleep/wake issues, and other small items that cause the AMD cards to perform worse in certain benchmarks, but fixes are in the works. Once corrected, these cards should far outperform the NVIDIA cards with the WX 4170 beating out the GTX 780M, our current top performer.
AMD WX7100
Recognized by macOS as a Radeon RX 580, this card can use a combination of custom VBIOS and OpenCore to enable native brightness control, Target Display Mode, boot screens, and more. See
THIS POST for ROMs, OpenCore implementation, and more info.
There has been recently some confusion about the
identification of this product.
@Nick [D]vB has obviously a working
card with number
109-C95847-00C_02, user
@Pascal Baillargeau has a card working with number
109-C95847-00D_02, user
@jborko failed
checking a card with number
109-C95847-00C_02 , user
@JoeOIVOV failed
checking a card and this ID
109-C95847-00D_02 as well as user
@meggle with a 00D variant. Additionally user
@Vego17 recently got a card with
109-C95847-00C_02
not working in his iMac 2011 but running fine in a
Dell Precision 7710 laptop. So you may get perfectly fine products simply not posting/running/working with you iMac. Currently we simply do not know the reason for this behaviour.
Right now we have at least one 00C and one 00D reported to work.
Check the online offers carefully.
AMD WX4170
Recognized by macOS as a Radeon RX 560, but some come with a blank EEPROM and a missing resistor.
Working models with EEPROM are scarce, but like the WX7100, this card can use a combination of custom VBIOS and OpenCore to enable native brightness control, Target Display Mode, boot screens, and more. See
THIS POST for ROMs, OpenCore implementation, and more info. User
@jborko did a write up
HERE on their experience installing a WX4170.
AMD WX4130/WX4150 - 09/10 Only
Same features as AMD WX4170, user
@internetzel has posted his modified
VBIOS based on the work of
@Nick [D]vB
You will have to use the very same
OpenCore configuration as described in the former AMD WX4170 section. This card needs to have an EEPROM chip on board, too. There are multiple versions of this card - only the "Dell" branded versions currently work. These are the current work in progress and are still in their infancy of testing.
Note - These WX 4130/4150 are not detected by the 2011 iMacs for some reason, and therefore are currently incompatible. Even worse some models are not detected in any iMac model late 2009 to mid 2011).
~~~~~~~~~~
Original Post from @MichaelDT June 14th, 2013.
I will be attempting to upgrade the MXM card in my 2011 21.5 iMac from the factory 6770m 512mb to a NVidia 675m 2GB. I choose this card because the chipset already has support from 10.8.3 onwards and affordability for an experiment. I am hoping that it will work without flashing like many of the other non MXM modern graphics cards (UEFI support) do in 64bit EFI Mac Pros ( I may loose the initial boot screen). But if all else fails I will attempt a flash. I will report back my findings when the card arrives (from Hong Kong). Wish me luck hopefully this will give those of us with the last modular iMac a path forward.
www.techpowerup.com
forums.macrumors.com
