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

[Ausdauersportler]

I'm sorry. i thought to have already added it but i did it in the wrong place ( section about and not signature ) 😅

i hope that the gpu isn't dead , i don't have another pc with an mxm slot to test if it works, moreover i can see that i'm not the only one with this issue with a k2100m and if the mojority of gpus are dead only who is lucky can do this upgrade, isn't it?

Last December everything was quite on this market, then @Nick [D]vB and later @nikey22, @stephle and @internetzel published Apple compatible BIOS versions for nearly 20 models and a gold rush started on these cards. Prices doubled and tripled in May for the K2100M and K1100M and of course every broken electronic garbage hit this overheated market, too.

And a lot of iMac users happily jumped onto that train. So we are here, some guys simple cannot flash or install a card on a heat sink, others get a dead cheap one. Greed is not a good advisor in shopping, in every investment.

I wrote the post about the boot chime loop. You can only break it by getting the card out, sometimes the PRAM buffer batterie, too (the CR2032 on front our back of the logic board). Then install the board without a GPU, do three PRAM resets in a row and reinstall the GPU. I know it is a pain ....

 

[Zorrogarcia]

Good point, though the CH341A only requires a free USB port (i.e. laptop) and they are more easily obtained. I had been wondered if these “PCI-E to MXM3.0” adapters would work, so thanks for answering that. Do you plug it directly to the motherboard’s PCI-E 1X slot, or use a riser with “stable power supply” as your link recommends? If so which riser do you use/recommend? Perhaps something like this?

PCI Express Adapter PCI-E 1X to 16X Slot Riser Card Extender USB 3.0 Cable 4Pin Dual 6pin Power Supply for BTC Miner Mining

So, according to you, what should i have to do? Use the CH341A that i have already bought ( but i can give it back,so that's not a problem) or buy an mxm adapter and flash with it ?(in that case i have to wait at least 3 weeks)😅

sorry guys but i'd like to have an opinion by someone who has a better knowledge than me of those arguments😅

 

[Ausdauersportler]

So, according to you, what should i have to do? Use the CH341A that i have already bought ( but i can give it back,so that's not a problem) or buy an mxm adapter and flash with it ?(in that case i have to wait at least 3 weeks)😅

sorry guys but i'd like to have an opinion by someone who has a better knowledge than me of those arguments😅

use the clip and start reading post #1 instead of having esoteric discussions about solutions nobody has tested before

 

[Zorrogarcia]

Last December everything was quite on this market, then @Nick [D]vB and later @nikey22, @stephle and @internetzel published Apple compatible BIOS versions for nearly 20 models and a gold rush started on these cards. Prices doubled and tripled in May for the K2100M and K1100M and of course every broken electronic garbage hit this overheated market, too.

And a lot of iMac users happily jumped onto that train. So we are here, some guys simple cannot flash or install a card on a heat sink, others get a dead cheap one. Greed is not a good advisor in shopping, in every investment.

I wrote the post about the boot chime loop. You can only break it by getting the card out, sometimes the PRAM buffer batterie, too (the CR2032 on front our back of the logic board). Then install the board without a GPU, do three PRAM resets in a row and reinstall the GPU. I know it is a pain ....

Last December everything was quite on this market, then @Nick [D]vB and later @nikey22, @stephle and @internetzel published Apple compatible BIOS versions for nearly 20 models and a gold rush started on these cards. Prices doubled and tripled in May for the K2100M and K1100M and of course every broken electronic garbage hit this overheated market, too.

And a lot of iMac users happily jumped onto that train. So we are here, some guys simple cannot flash or install a card on a heat sink, others get a dead cheap one. Greed is not a good advisor in shopping, in every investment.

I wrote the post about the boot chime loop. You can only break it by getting the card out, sometimes the PRAM buffer batterie, too (the CR2032 on front our back of the logic board). Then install the board without a GPU, do three PRAM resets in a row and reinstall the GPU. I know it is a pain ....

Update: i've investigated on the gpu with a lot of patience and i saw only right now a little scratch on the gpu die and i think that the problem is that ... i did't see it because frontally it's not visible but with the light on the right way you can cleary see it .. so i think that u were right , i wasted money and time ... sad story😖

 

[Ausdauersportler]

Update: i've investigated on the gpu with a lot of patience and i saw only right now a little scratch on the gpu die and i think that the problem is that ... i did't see it because frontally it's not visible but with the light on the right way you can cleary see it .. so i think that u were right , i wasted money and time ... sad story😖

You are the first on the thread being able to diagnose a gpu just by watching it.

 

[Zorrogarcia]

You are the first on the thread being able to diagnose a gpu just by watching it.

No no , i only suppose that by the results that i have had till now , but i'v never said to know everything or something similar , cause if that was the case i wasn't here right now writing to you in this thread.

i didn't want to be rude sorry 😅

 

[KennyW]

Update: i've investigated on the gpu with a lot of patience and i saw only right now a little scratch on the gpu die and i think that the problem is that ... i did't see it because frontally it's not visible but with the light on the right way you can cleary see it .. so i think that u were right , i wasted money and time ... sad story😖

I am not so sure about the small crack as the culprit.
The BIOS chip should be the one near left upper corner below the screw hole.
It is a SOP8 chip that can hold the ch341a clip without a problem.
Rather, the glue at the four corners alerts me of a fake / refurnished module !
I have received a similar blue board for a presumably AMD WX4150 with these glues.
I examine the original BIOS which is flashed as HD5800 with extraction from my programmer.
It also boot-loops and not stops or works with new flashed BIOS, though yours is an nVidia.
Flash it and report.

 

[Nguyen Duc Hieu]

Update: i've investigated on the gpu with a lot of patience and i saw only right now a little scratch on the gpu die and i think that the problem is that ... i did't see it because frontally it's not visible but with the light on the right way you can cleary see it .. so i think that u were right , i wasted money and time ... sad story😖

There are 2 missing chips on the right of the card. Maybe this is the cause of your card not working in other machines than the HP laptop.

 

[mdgm]

I'm wanting to use UEFI Windows 10 but with the stock GPU. Can I use the Open Core from this thread even though I have the stock GPU?

 

[herrdude]

I'm wanting to use UEFI Windows 10 but with the stock GPU. Can I use the Open Core from this thread even though I have the stock GPU?

Why wouldn't you post that question in the main iMac thread? That would allow others with a similar question to find it more easily. This thread is about changing the GPU, which has nothing to do with your question.

Cheers!

 

[mdgm]

Why wouldn't you post that question in the main iMac thread? That would allow others with a similar question to find it more easily. This thread is about changing the GPU, which has nothing to do with your question.

Cheers!

Thanks. Posted here: https://forums.macrumors.com/thread...mac-gpu-to-fix-windows-10-uefi-audio.2273356/

 

[vep]

after the installation and the PRAM reset, iMac keeps rebooting just after the classic bong and third diagnostic LED is off.

I had similar issue, careful reconnect of the LCD connector on the main board helped to resolve.

 

[Ed Hartouni]

Not that this is going to help... but for all of you who are struggling through the GPU upgrade of your beloved iMac know that there have been at least 203 successful upgrades recorded on the Unigine Valley performance page from 4/24/2020 to 12/3/2020 (today of this post).

I went through the process of discovering that the first K1100M I bought was defective and had to buy another. I was lucky that the second one worked and I'm running Catalina on my 2011 21.5" iMac. It is work to figure out that you have a bad GPU board... especially because Mac users aren't used to doing anything like the hardware and software modifications required for this upgrade. Being systematic helps, also, having another (the original?) GPU card that works lets you eliminate many possible problems.

Of the 203 successfully upgraded iMacs, the distribution is:

2009 27"....... 28
2010 21.5".... 9
2010 27"....... 22
2011 21.5".... 26
2011 27".......122

the 27" has a lot of successful upgrades (172). I think this makes sense, those machines are truly meant to be upgraded. Also, 2011 was the apex of iMac upgradeability, that model year has 146 successes (something about the title of the thread?). [there may be double counting for entries that are posted for the same machine in different configurations, however, this means that the person doing the upgrade was successful at multiple modifications, so take heart!]

The successful upgrade GPU cards are:

K610M	5​		WX4130	10​
K1100M	14​		WX4150	1​
K2100M	43​		WX4170	19​
K1000M	2​		WX7100	15​
K2000M	1​		RX480	1​
K3100M	6​
K4100M	18​
K5000M	1​
K5100M	3​
GTX 765M	6​			​
GTX 770M	11​		HD 4670	1​
GTX 780M	20​		HD 4850	2​
GTX 880M	6​		HD 5670	2​
GTX 860M	2​		HD 5750	1​
GTX 870M	1​		HD 6750M	1​
			HD 6770M	6​
GTX 970	1​		HD 6970M	8​

(green means the card shows up on Page 1/Post 1!)

The K2100M has the been used the most, followed by the GTX 780M, WX4170, and K4100M .

This table will obviously change as time goes on...
...so not only is it possible to upgrade your iMac GPU, it has been done frequently at a rate of more than one successful upgrade a day since March 2020...

 

[woname]

Hello everyone. Just installed successfully K2100M to 27" imac. Everything is fine, but I cant download "iMac OpenCore Loader.dmg" from Google Drive (they says its a virus). Please, can someone reupload this to anywhere else. Cant find any other links to it with search, sorry.

No, you won't get a picture on the stock vBIOS without a back-light mod,

AMD users should flash the GOP vBIOS attached, you can do it from windows.

Then use OpenCore to get boot-screen and brightness control with no other mods!

AMDVBFlash / ATI ATIFlash 5.0.567 Download

AMD AMDVBFlash is used to flash the graphics card BIOS. The version released by ATI was called ATIFlash or just WinFlash. It supports all AMD Radeo

www.techpowerup.com

Download: iMac OpenCore Loader.dmg


FEATURES:

[1] Native brightness control on Quadro K1100M & K2100M cards.

(more cards may be added in the future through vBIOS updates)

[2] Target Display Mode on Quadro K1100M & K2100M cards.

[3] Real-time hardware monitoring using HWMonitor app:

Nvidia GPU Die Temp + GPU, VRAM & CPU core Frequencies.

[4] Reduced boot-screen delay, no more random black-screen boots.

[5] OpenCore + rEFInd boot-pickers on AMD cards with NO MODS!

(allows bootscreen & native brightness control simultaneously)

[6] SideCar + Video acceleration on new AMD cards (Mojave+)

Huge H264 & HEVC video encoding speed improvements in FCPX etc

Playback of DRM protected streaming content (Netflix 4K etc)


2011 iMacs only -

[7] UEFI Windows: Sound fix for HDAudio code 12 driver error,

can also fix some ThunderBolt eGPU resource issues in Windows.

(Enable DSDT in ACPI section of the OpenCore configuration tool)

[8] Mojave & Catalina: Integration of SandyBridge iGPU Kexts

required for the AirPlay + Sleep + GVA QuickSync video fixes

Catalina needs IOSurface.kext replacing FIRST, more details here:

2011 iMac Graphics Card Upgrade

EDIT: 7/28/20 Please download the newest Lilu/WhateverGreen kexts from Github, they constantly change. EDIT: 4/17/20 An additional AppleIntelSNBGraphics.kext has been added to the pack to include board ID for iMac Pro/AMD-WX Series Config.plist. You can now have working sleep when your board ID...

forums.macrumors.com

INSTALLATION:

Restore the image to an SD card or USB stick, I do not recommend installing to a non-removable drive. If using an AMD card show hidden files and extract the AMD config.plist file inside the /EFI/OC/ folder. Set the "Catalina Loader" drive as the default boot disk in system preferences or by using Ctrl+Enter from the Apple boot-picker. If you have problems booting delete any Lilu or Whatevergreen kexts from S/L/E, to disable OpenCore just remove the drive and do an NVRAM reset.


WARNING:

Congratulations, you are now running a Hackintosh! I have done some basic safety checks but I can't test everything, there is a non-zero risk that something will go spectacularly wrong. I accept NO responsibility if Apple ban your accounts or if your iMac blows-up, wipes all your data, and injures your cat... Make sure you have current back-ups of all your drives, and use the RomTool to make a back-up of your iMacs BootRom so it can be restored in case of corruption (very unlikely, but possible). Configuration tools are included, be careful - here be dragons!


Based on "Catalina Loader" by Rastafabi.

Thanks to Highvoltage12v & Ausdauersportler for testing.

Full credit to all the original developers & those who shared essential information.



Better late than never...

 

[Ausdauersportler]

Not that this is going to help... but for all of you who are struggling through the GPU upgrade of your beloved iMac know that there have been at least 203 successful upgrades recorded on the Unigine Valley performance page from 4/24/2020 to 12/3/2020 (today of this post).

I went through the process of discovering that the first K1100M I bought was defective and had to buy another. I was lucky that the second one worked and I'm running Catalina on my 2011 21.5" iMac. It is work to figure out that you have a bad GPU board... especially because Mac users aren't used to doing anything like the hardware and software modifications required for this upgrade. Being systematic helps, also, having another (the original?) GPU card that works lets you eliminate many possible problems.

Of the 203 successfully upgraded iMacs, the distribution is:

2009 21.5".... 0
2009 27"....... 28
2010 21.5".... 9
2010 27"....... 22
2011 21.5".... 26
2011 27".......122

the 27" has a lot of successful upgrades (172). I think this makes sense, those machines are truly meant to be upgraded. Also, 2011 was the apex of iMac upgradeability, that model year has 146 successes (something about the title of the thread?). [there may be double counting for entries that are posted for the same machine in different configurations, however, this means that the person doing the upgrade was successful at multiple modifications, so take heart!]

The successful upgrade GPU cards are:

K610M	5​		WX4130	10​
K1100M	14​		WX4150	1​
K2100M	43​		WX4170	19​
K1000M	2​		WX7100	15​
K2000M	1​		RX480	1​
K3100M	6​
K4100M	18​
K5000M	1​
K5100M	3​
GTX 765M	6​			​
GTX 770M	11​		HD 4670	1​
GTX 780M	20​		HD 4850	2​
GTX 880M	6​		HD 5670	2​
GTX 860M	2​		HD 5750	1​
GTX 870M	1​		HD 6750M	1​
			HD 6770M	6​
GTX 970	1​		HD 6970M	8​

(green means the card shows up on Page 1/Post 1!)

The K2100M has the been used the most, followed by the GTX 780M, WX4170, and K4100M .

This table will obviously change as time goes on...
...so not only is it possible to upgrade your iMac GPU, it has been done frequently at a rate of more than one successful upgrade a day since March 2020...

if I were to do it over again, I'd probably go with a WX4130... (or WX4150 depending on availability).

Some add ons:

1. There are at least 4x RX480 upgrades known to me from this thread: 3x 2010, 1x 2009
2. From all what I experienced with more than 10 upgrades I did personally the 2010 model is definitely the most compatible one, it can run most if not all of the AMD cards known being problematic in the 2011 and it does not show the nasty 2009 bug when your will have a black screen using a Nvidia card unless you boot into an macOS with a patched AGC (and to make it worse, after a PRAM reset you get back the black screen).
3. the 21.5" 2009 is not compatible at all according to our own list on the first post
4. It would be nice to have a script pulling this data/table once a month out of the UNIGINE website and show it here...
5. We should encourage all the people here to run and upload these benchmarks

Thanks for your nice work!

 

[Ausdauersportler]

Hello everyone. Just installed successfully K2100M to 27" imac. Everything is fine, but I cant download "iMac OpenCore Loader.dmg" from Google Drive (they says its a virus). Please, can someone reupload this to anywhere else. Cant find any other links to it with search, sorry.

Go to post #1 and read the open core section, it has the link to the most recent image. Try to use a different browser to come around the message may be another solution and there are a million tools to force downloads.

 

[Pascal Baillargeau]

How to patch DSDT to make sound work in Windows10 UEFI

To make sound work in Bootcamp Windows UEFI, you could need to patch DSDT. We have to remove Window's 32-bit PCIe allocation constraint and allow the use of a 64-bit PCIe address space.

You need Maciasl to extract your own DSDT.

Search for DWordMemory. After the last DWordMemory we will inject a QWordMemory.

QWordMemory (ResourceProducer, PosDecode, MinFixed, MaxFixed, Cacheable, ReadWrite,
    0x0000000000000000, // Granularity
    0x0000000C20000000, // Range Minimum
    0x0000000E0FFFFFFF, // Range Maximum
    0x0000000000000000, // Translation Offset
    0x00000001F0000000, // Length
    ,, , AddressRangeMemory, TypeStatic)

Compile your modified DSDT and save it as ACPI Language Machine Binary (.aml).
Then you can inject this modified DSDT via OpenCore.

 

[Pascal Baillargeau]

How to patch DSDT to make sound work in Windows10 UEFI

To make sound work in Bootcamp Windows UEFI, you could need to patch DSDT. We have to remove Window's 32-bit PCIe allocation constraint and allow the use of a 64-bit PCIe address space.

You need Maciasl to extract your own DSDT.

View attachment 1686432

Search for DWordMemory. After the last DWordMemory we will inject a QWordMemory.

View attachment 1686433

QWordMemory (ResourceProducer, PosDecode, MinFixed, MaxFixed, Cacheable, ReadWrite,
    0x0000000000000000, // Granularity
    0x0000000C20000000, // Range Minimum
    0x0000000E0FFFFFFF, // Range Maximum
    0x0000000000000000, // Translation Offset
    0x00000001F0000000, // Length
    ,, , AddressRangeMemory, TypeStatic)

Compile your modified DSDT and save it as ACPI Language Machine Binary (.aml).
Then you can inject this modified DSDT via OpenCore.

The modified DSDT included in Catalina Loader to make sound work in Windows 10 UEFI can be created this way. You could find interesting to create it yourself beginning from your own DSDT and apply the modification needed.

 

[Borak]

Friends, this question goes to whoever installed the GTX 780M.

How to achieve maximum brightness?

iMac 27" Mid 2011 - i5 - 3.1 GHz - GPU - Nvidia GTX 780M - Flashed (nikey22 + xanderon method) - macOS Catalina - SSD 240GB + HD 1TB - 24GB RAM.

Thanks.

 

[KennyW]

Not that this is going to help... but for all of you who are struggling through the GPU upgrade of your beloved iMac know that there have been at least 203 successful upgrades recorded on the Unigine Valley performance page from 4/24/2020 to 12/3/2020 (today of this post).

I went through the process of discovering that the first K1100M I bought was defective and had to buy another. I was lucky that the second one worked and I'm running Catalina on my 2011 21.5" iMac. It is work to figure out that you have a bad GPU board... especially because Mac users aren't used to doing anything like the hardware and software modifications required for this upgrade. Being systematic helps, also, having another (the original?) GPU card that works lets you eliminate many possible problems.

Of the 203 successfully upgraded iMacs, the distribution is:

2009 27"....... 28
2010 21.5".... 9
2010 27"....... 22
2011 21.5".... 26
2011 27".......122

the 27" has a lot of successful upgrades (172). I think this makes sense, those machines are truly meant to be upgraded. Also, 2011 was the apex of iMac upgradeability, that model year has 146 successes (something about the title of the thread?). [there may be double counting for entries that are posted for the same machine in different configurations, however, this means that the person doing the upgrade was successful at multiple modifications, so take heart!]

The successful upgrade GPU cards are:

K610M	5​		WX4130	10​
K1100M	14​		WX4150	1​
K2100M	43​		WX4170	19​
K1000M	2​		WX7100	15​
K2000M	1​		RX480	1​
K3100M	6​
K4100M	18​
K5000M	1​
K5100M	3​
GTX 765M	6​			​
GTX 770M	11​		HD 4670	1​
GTX 780M	20​		HD 4850	2​
GTX 880M	6​		HD 5670	2​
GTX 860M	2​		HD 5750	1​
GTX 870M	1​		HD 6750M	1​
			HD 6770M	6​
GTX 970	1​		HD 6970M	8​

(green means the card shows up on Page 1/Post 1!)

The K2100M has the been used the most, followed by the GTX 780M, WX4170, and K4100M .

This table will obviously change as time goes on...
...so not only is it possible to upgrade your iMac GPU, it has been done frequently at a rate of more than one successful upgrade a day since March 2020...

if I were to do it over again, I'd probably go with a WX4130... (or WX4150 depending on availability).

I got your same opinion that WX4130 would be the most cost-effective one and of higher performance than the nVidia, though I am biased with my "signature" you can observe. WX4130 has fewer variations in the market, and the two green Dell cards of v1.1 that I got work even unflashed, though without internal display. They are of the comparable price of the low end card of nVidia but performance-wise are much better in the Metal score (~4 fold) with more fluid Finder interface due to the deeper Metal API integration in Catalina, without the bit-depth issue of nVidia cards on startup. Our good developers have also tuned and enabled all the shaders as the WX4150 so that their performance are really very close. Getting a WX4150 is more like a lottery. I got two and both not working.

If you want a higher performance, the RX480 is really a better choice than the WX7100 at almost half its cost but near same performance. There seem to be only one version of the board and should be flashable consistently in 2009 & 2010, although unfortunately not so for 2011 which is more picky 😆 There are also good supply in the market of seemingly NEW cards from OEM factory. I think it matches just right for the iMac we own, might be even a little overkill for the apps we run in that 10 years old iMac. The extra $100 for the extra 4GB RAM for WX7100 is not worth it unless probably you are deeply into graphics or videos editing. If so, I would strongly advise to spend some more to get the M1 MacMini instead of a WX7100 for your vintage iMac.

But of course the choice and valuation (including the 27" screen) finally depend on one's usage pattern and targeted task. Just my subjective opinion with no direct working with the nVidia GPUs, and probably only applicable to iMac 27" 2010. Our BIOS developers have certainly broader experience and perspective.

 

[vastunghia]

My HP WX4150 works, with a small issue.
(Maybe I got lucky, maybe you won't be lucky as I am, bear that in mind if you ever buy your own HP WX4150)

Photo is in this post. #76

I used GOP ROM to flash, I used a HP 800G1 USDT, Windows 10, and Atiwinflash.
The link to the ROM is next to WX4170 in the table on #1

After install it to my iMac 2010 (running High Sierra), I powered it on.
Normal chime, normal quiet fans, the machine was cool, nothing went crazy.
But the screen was pit black (no light, at all), however long I waited, reset NVRAM, etc....
Feeling despair, I hooked it to the HP 800 G1 to see if Target Display Mode work, before reporting here for any suggestion.
Target Display Mode did work. Windows recognized the 2k resolution, and display beautifully.
What a relief! I didn't screw up with the installation. (or did I?)
So I turn-off the Windows PC, thinking about putting back the HP5670 to my iMac.
...
What the hell? I saw the log-in screen on my iMac...
And I log-in....

Now I got a Radeon Polaris 4096MB GPU recognized already...

With brightness control, yes.
Sleep mode: Yes.
Just have to kick-start it with Target Display Mode ....

If your HP WX4150 behaved the same, maybe you could try Target Display Mode as I did. (This is for your guys who already bought the HP cards, I do not encourage you to buy HP WX4150, it's risky.)

P/S 1: I edited my post adding (running High Sierra) in case I change my signature later. It may sound inconsistent with internetzel's post below, but he was giving me great advice on the OS version.

P/S2: When I connected my Dell 2407WFP to the miniDisplayport (miniDisplayPort to D-SU adapter), it just worked and displayed on both screens. No need to KickStart anymore. I now have a computer I can write home about.

Thank you all, I admire your works a lot. Greatly appreciate!

Ciao,

I'm very interested in replicating your experience. I found a very similar graphics card (see below) so I'm hoping it could work.

However, if I understand correctly, one key step was to use TDM as a kick-starter. Since I own a Mid-2010 21" iMac, I'm afraid I cannot use this method.

Could anyone advice?

Second question: did you use an additional copper plate + thermal paste as suggested here?

Last question: is this card confirmed to be working in Big Sur as well?

Thank you in advance.

Sergio

 

[KennyW]

Ciao,

I'm very interested in replicating your experience. I found a very similar graphics card (see below) so I'm hoping it could work.

However, if I understand correctly, one key step was to use TDM as a kick-starter. Since I own a Mid-2010 21" iMac, I'm afraid I cannot use this method.

Could anyone advice?

Second question: did you use an additional copper plate + thermal paste as suggested here?

Last question: is this card confirmed to be working in Big Sur as well?

Thank you in advance.

Sergio

There is no need for TDM. Just connect an external display or a dummy mini-DisplayPort adapter will do. But that occurs only in High Sierra. In Catalina, it works flawlessly without the dummy adapter or connection.

And the copper plate is a necessity if you don't want to burn your GPU chip in long term.
I have tested and measured the temperature difference in my post.

 

[Ausdauersportler]

I did the link above and I think you have to hold the Alt/option button regardless. Mine seems to be that way anyways.

Tried to read the first post here an search for the common problems?

 

[Ausdauersportler]

OK, first of all, all you guys who made this work are amazing and thank you! My mid-2011 just came back to life! I can also confirm that an HP K2100m card worked fine for me using the USB drive bios flash tool. I have it running catalina now and everything seems 100% except like @luchura when I turn my computer on, it will not work on the display unless I reset PRAM every time (Command+Option+P+R) and it works when it reboots itself from this command. Until the next time I shutdown. Spent most of the day digging through the forum and not sure what the cause is. anyone have any idea?

Read the first post - this is the most prominent issue....known since Sierra came out.

 

[Ausdauersportler]

Ciao,

I'm very interested in replicating your experience. I found a very similar graphics card (see below) so I'm hoping it could work.

However, if I understand correctly, one key step was to use TDM as a kick-starter. Since I own a Mid-2010 21" iMac, I'm afraid I cannot use this method.

Could anyone advice?

Second question: did you use an additional copper plate + thermal paste as suggested here?

Last question: is this card confirmed to be working in Big Sur as well?

Thank you in advance.

Sergio

The third nearly identical message:
You possibly did not read the first post about the AMD cards, too. There is a 90% chance that these cards will not post in the 2011 model. But since you already bought it please report after installation if you got a bootable system.