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Try this (which is part of the original docs made by @xanderon):

Code:
./nvflash_linux --protectoff
./nvflash_linux -6 NEWBIOS.rom

If this fails you need to buy a CH341A clip programmer and use the flashrom software.
where can I buy that for a good price and yeah it did fail:

NVIDIA Firmware Update Utility (Version 5.692.0)


Copyright (C) 1993-2021, NVIDIA Corporation. All rights reserved.
Checking for matches between display adapter(s) and image(s)...

Adapter: NVS K1 USM (10DE,0FE6,103C,2256) S:00,B:01,D:00,F:00

EEPROM ID (EF,3012) : WBond W25X20A 2.7-3.6V 2048Kx1S, page
EEPROM ID (EF,3012) : WBond W25X20A 2.7-3.6V 2048Kx1S, page
NOTE: Only IFR present:

NOTE: Skipping Board ID and Device ID checks.

NOTE: EEPROM does not contain board ID, skipping board ID check.

WARNING: None of the firmware image compatible PCI Device ID's

match the PCI Device ID of the adapter.

Adapter PCI Device ID: 0FE6

Firmware image PCI Device ID: 0FF6

WARNING: Firmware image PCI Subsystem ID (1028.15CC)

does not match adapter PCI Subsystem ID (103C.2256).

NOTE: Exception caught.

Nothing changed!

ERROR: GPU PCI Device ID mismatch.
 
I tried your bios - it works.
But, your bios is 2016. And my original bios is 2017. More recent. It will be better if it is modified. Thanks.
In our old iMac case, we can't just choose the latest VBIOS and expect it to work better than older ones.
The provided VBIOS is specially chosen and modified in order to cooperate well with the macOS drivers; other versions of VBIOS often break throttling and boosting before and/or after waking up from sleep.
For some cards it's older versions that work better and for others later versions work better.
 
** hp AMD Radeon HD6770M Mac Edition ROM **

View attachment 1845691


The following is an iMac rom for the Hewlett-Packard AMD Radeon HD6770M 1GB cards.
It will be a replacement to the frequently failing Apple AMD Radeon 6770M 512MB cards.
These cards require hardware modification to make them work properly in the iMac:

SPI EEPROM:
Firstly, these cards come without an SPI EEPROM chip because the base HP laptop uses the vbios off the system bios to load the GPU data.
You will therefore need a proper EEPROM chip:
- 1Mbit sized SOIC-8 chip: Pm25LD010
View attachment 1845692 View attachment 1845693


RESISTOR NETWORK:
If we look at a schematic diagram we can see that we need configuration startup resistors in the following format "1-0-1" to get the card to POST and be recognized by the iMac. These resistors basically tell the card that it should load the vbios off the card and not from the system bios:

View attachment 1845696

The HP card is missing 2 resistors that make this possible, the 10KΩ at location R503 and 5KΩ at location R492. Thank you to @edwardgeo for his excellent work in testing out these resistor values and determining the correct ones for us. I believe he was able to confirm that is POSTed in a Elitebook HP laptop. You will need micro-soldering skills. I sourced these 2 resistors from a old router.


VRAM CONFIGURATION (VRAM_Info):
View attachment 1845697

We need a table that will work with this vram type. This is a different ram than that used in the Dell M5950. The M5950 uses -AFR. You can use any vram table as long as it conforms to the 1.35V standard and has initialization for -BFR Hynix rom.


EFI 1.1 ROM:
The PC UEFI rom is useless. This card is completely compatible with the ATI Radeon 01.00.544 EFI rom which contains the necessary Whistler video adapter driver and assigns the Hydrilla framebuffer inherent to all macOS versions. I have done testing only on High Sierra.
The rest is history:
View attachment 1846007
View attachment 1845699View attachment 1845700


This is insanely great!
-Steve Jobs


**Update**:
9-24-2021 testing thermal chip, possible addr collision, not reporting a temp on Macfans.
Using HP blue green pcb m5950 added EEPROM patch resistor, macOS 10.13.6 uefi Windows10 everything is normal and perfect, mbr Windows7 graphics card driver can not be installed to try multiple versions of the driver file including bootcamp driver package inside the 6770m driver also shows the same successful installation of the driver It does not work properly, Windows 7 driver problems do not know if it can be fixed.

Translated with www.DeepL.com/Translator (free version)
 

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Today I also purchased three HP wx4170, and so I received a look at the physical photo shoot to see which resistors are missing feedback results.

Maxwell m4000m Pascal p3000 are tested not bad, macOS can only 10.13.6 Windows 10 is very perfect.

I'm still looking for the right Turing amp mxm graphics card to test.
 

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It is strange that in 10.13.6 unigine valley showed 60 frames per second.
And in Big Sur 11.3-11.6 shows 32 frames per second. Why is it so slow? In NVIDIA, everything is usually displayed the same way on the two systems. But AMD WX7100 shows different tests...

32.png
60.png
 
It is strange that in 10.13.6 unigine valley showed 60 frames per second.
And in Big Sur 11.3-11.6 shows 32 frames per second. Why is it so slow? In NVIDIA, everything is usually displayed the same way on the two systems. But AMD WX7100 shows different tests...
Please run full benchmark using the exact same settings in both macOS versions as described on the very first post of this thread and post only those complete results, not snapshots.
 
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Today I also purchased three HP wx4170, and so I received a look at the physical photo shoot to see which resistors are missing feedback results.

Maxwell m4000m Pascal p3000 are tested not bad, macOS can only 10.13.6 Windows 10 is very perfect.

I'm still looking for the right Turing amp mxm graphics card to test.
Since we have a now dedicated thread for this separate Windows topic please use this other thread :)
 
Windows theme threads where I don't see oh can hint link
Thank you
Are you serious? You already posted on the thread. If you believe the name does not fit ask the original poster to change it.

I appreciate your help here, but using Nvidia video cards running only High Sierra (unsupported) and Windows is really another story and a different topic.
 
Hi,
I've acquired Nvidia Quadro K3100M and with the BIOS K3100M_V4.rom
it does work reasonably well for me in both Windows 10 & MacOS Big Sur

The only question I have and really looking for any advice:
is it possible to connect 2nd external screen with such (or maybe some other Nvidia cards) a card?

I really need to have 2 external screens (I do use iMac 2011 27") which used to work fine with the original AMD card, but with Nvidia one only 1 display port is working

Best Regards
 
Hi,
I've acquired Nvidia Quadro K3100M and with the BIOS K3100M_V4.rom
it does work reasonably well for me in both Windows 10 & MacOS Big Sur

The only question I have and really looking for any advice:
is it possible to connect 2nd external screen with such (or maybe some other Nvidia cards) a card?

I really need to have 2 external screens (I do use iMac 2011 27") which used to work fine with the original AMD card, but with Nvidia one only 1 display port is working

Best Regards
Try to find some rare and expensive old Thunderbolt 1/2 docks and connect it to the second TB port. There is no other way known currently.

IMHO the one port limitation applies also to the AMD and all other NVIDIA cards.
 
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Try to find some rare and expensive old Thunderbolt 1/2 docks and connect it to the second TB port. There is no other way known currently.

IMHO the one port limitation applies also to the AMD and all other NVIDIA cards.
Thanks for the quick reply.
Is the reason known why original AMD cards are working fine with 2 ports and more modern ones doesn't?
 
Thanks for the quick reply.
Is the reason known why original AMD cards are working fine with 2 ports and more modern ones doesn't?
No, obviously not!

Surely there is a technical reason why the original AMD cards work with two ports while no replacement card cannot do this. This thread is 7 years old, believe me, we are not hiding knowledge on purpose. The BIOS developers simply could not reverse engineer it during the last years.

So do not expect a fix!

BTW: It is one of the seven problems described on the first post!
 
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No, obviously not!

Surely there is a technical reason why the original AMD cards work with two ports while no replacement card cannot do this. This thread is 7 years old, believe me, we are not hiding knowledge on purpose. The BIOS developers simply could not reverse engineer it during the last years.

So do not expect a fix!

BTW: It is one of the seven problems described on the first post!
Thanks for the info :)
Sorry if this question is too silly (and I have doubts I'll follow that way due to associated costs) but:

The Apply Thunderbolt display should be able to work as a 2nd external scree, right?
As it actually uses thunderbolt and not a display port, or I'm missing something conceptually?
 
I figured it out. Openkore works better without the loader than with the Openkore loader. Screenshots below.
hiigh-sierra.png
big sur no opencore.png
big sur in opencore.png
 
I figured it out. Openkore works better without the loader than with the Openkore loader. Screenshots below.
Again, use the very same settings in your benchmarks when you want to compare the results. As a scientist it really hurts to see this :)

Hint: Check the quality setting!
Note: Do a series of at least 5 benchmarks with each setting and post only the numbers, not the pictures.
Edit: It is OpenCore :cool:
 
Experimental AMD W5170M 2GB support (AMD Radeon R9 M375 2GB)

This card has been produced in many variants, currently I know of at least three different types and ident strings:

TypeidentBIOS versiondevice-idworking
Green AMD PCB109-C93157-00A_03W5170M6820yes
Blue AMD PCB109-C42271-01_02W5170M6820most likely

Sometimes this card will be advertised as AMD W5170M 2GB version (AMD re-branding). This will be the Green card.

Warning:
This card is easy to install but complex to manage during the initial software installation. You need to install OpenCore in advance and add the changes posted before booting into macOS.

Important:
Use the W5170M vBIOS for both the green and blue card!

After installing the card it will not simply boot directly into any macOS version (WindowServer crash) unless you install and use OpenCore and apply the settings described below (I will try to get the changes added to OCLP, later).

So you need to install OpenCore onto your boot disk before booting in your current installation in normal multi user mode.

In case you have a working system before changing the card just run OLCP, select the proper MXM GPU type to AMD (GCN) and build and install OpenCore to your system and reboot. Otherwise use another Mac to create the OC settings or create a OpenCore BootCD.

The settings needed are equivalent with adding radpg=15 -wegtree apdpmod=pikera to the boot-args in the config.plist of OpenCore.

This GPU type has been used in 2015 15" MacBookPro models.

Tested systems:
- iMac12,2: sleep/wake broken - black screen on cold boot needs PRAM reset each time
- iMac12,1: sleep/wake broken - black screen on cold boot needs PRAM reset each time

- iMac11,1: no problems
- iMac11,2: green AMD card has SMBUS problem, some temp sensor readings are weird, card needs a mod, red Dell card works fine!
- iMac11,3: no problems

Known issues:
- external display sync is difficult on all systems and needs the main LCD or the system to go to display sleep once after connecting the external display

Known features:
- Airplay is working until Catalina as with any other AMD metal card on iMac11,x and iMac12,2 (without using QuickSync)
- high metal scores
- boot screen with OpenCore
- brightness control working
- GPU power management working
- needs Sierra or better (AMD support)
- still full Monterey B9 support (no root patching needed unlike Kepler)

Performance:
- GeekBench Metal and OpenCL: > 10.000
- Valley AMD: 18.6 FPS, 778 Score
- MetalBench: 31 MRays/s
- CoreClock: 300 MHz idle - 850 MHz max
- MemoryClock: 150 MHz idle - 1125 MHz max
- PowerDraw: 5W idle - 35W max

Warnings:
- do not use this vBIOS on the Red DELL card, it will cause a bad flash and will make the card unusable
- do not flash the vBIOS from the DELL card onto the other two cards, it will cause a bad flash and will make the card unusable
- a bad flash prevents the iMac from booting and running the Linux flash utility, again!
- bad flashes can only be fixed by using clip programmer

News:
- OCLP 0.3.1 and later support this card. So you can update OC using OCLP in future. Nevertheless the boot strap process is complex since you cannot boot the normal macOS unless OC has been installed in advance!

Download:
GitHub W5170M
 

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First, please do not shout at us, we are perfectly able to read sentences set with non bold letters. Secondly no-one can promise you anything about the future and about non existing kernel panics and lastly I am pretty sure that the 4K acceleration has been mentioned in the first posts or the announcements made with the BIOS. It is a completely different questions which software version running on which operating system release will support which additional hardware in your (modded or stock) iMac. Check this with the software vendors site...

And please ask Apple the same question with supported hardware. I have never seen bug free software in my whole live.
Ok, then.
 
Hey guys so I have a 2011 27inch with a flashed 880 in it. The card works well when the computer is actually powered on. But shutting down the computer at night leads to an unresponsive power button in the morning. It works again when I take
the iMac apart and take the card out and put it back in though. Anyone have any similar experiences?
 
Just wanted to report my success in using one of Nick [D]vB's eBay cards to upgrade my 2011 27" i5 2500S. The card reports as an NVIDIA GeForce GTX 675MX 4 GB in About This Mac but is recognised elsewhere as a K3100m and it performs exactly as that card does in benchmarks. The install was straightforward, although (despite Nick saying that the heatsink did not require modding) the card sat with an approx 1-2mm 'tilt' so I ground off enough of the heatsink to make it sit flat. Everything worked as expected on booting up into High Sierra, except the max brightness was no longer as bright as before. Nick replied promptly to my query and said this was by design to manage temperatures, but he also gave me instructions and resources to 'fix' it should I wish. I did and everything now works as I want it to. I then used OpenCore to upgrade macOS to Big Sur, which went smoothly. All seems well, so far at least!

Anyway, thanks to Nick and all the other dedicated engineers and tinkerers who have given time to extending the lives of these old iMacs, it is much appreciated.

Cheers!

P.S. I upgraded my stock heatsink to the three-pipe version and keep an eye on temperatures with Macs Fan Control.
 
Without bootloader: MacOSX 10.13.6: Valley - Score 2976, FPS 72.
MacOSX 11.6: Valley - 2701, FPS 64. MetalBench - 179-240 MRays

With the OPENСORE loader: Mac OS X 10.13.6: Valley - 2974, FPS 71.1
Mac OS X 11.6 - Valley - 1696, FPS 40.5. Metal Bench - 110-167 MRays

Explain what is interfering with the OpenСore loader??? Why is it fast without a loader, but slow through the OpenСore loader???

On the macOS X 12 system, it is also slow through the bootloader.
 
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Hey guys so I have a 2011 27inch with a flashed 880 in it. The card works well when the computer is actually powered on. But shutting down the computer at night leads to an unresponsive power button in the morning. It works again when I take
the iMac apart and take the card out and put it back in though. Anyone have any similar experiences?

I have a similar issue with a 12,2 with a K3100M. If I shut down I get an "unresponsive power button" or if the machine goes to sleep it won't come back, I have to reboot (and have an unresponsive power button)

A couple of other thigns I've found:
  • If I push the power button a bunch of times, waiting about 2 seconds in between pushes the system will eventually come back. Sometimes it takes 20-30 pushes to get it
  • If I do a "restart" from the Mac menu the system will always reboot
  • If I shut it down and then wait about 10 minutes before restarting fewer power button pushes will be required

At some point I'm going to take it apart and try the card in another Mac. the 6970 card that was in this one is kaput so I can't go back to that one but never had the issue prior to changing the card. But until then I just prevent the system from going to sleep and hope that the power doesn't go off in the house
 
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Hey guys so I have a 2011 27inch with a flashed 880 in it. The card works well when the computer is actually powered on. But shutting down the computer at night leads to an unresponsive power button in the morning. It works again when I take
the iMac apart and take the card out and put it back in though. Anyone have any similar experiences?
I have 27 imac 2011. Sleep mode works without a bootloader and with a bootloader with these 3100, 4100, 880m, P3000, WX7100 video cards. I do not know why you have a bad sleep mode. I think your intel processor is not compatible. I have a 2600s 3.4 Ghz processor. Therefore, any video card works without problems with sleep mode. I can take a video.
 
Hi,
After reading this thread quite thoroughly, I ended up buying a k1100m to replace the dead gpu in my wife's 21.5 mid-2010 iMac. This card was the easiest to find and has full metal compatibility as of today. My purpose is not to get the most performant GPU but to ressurrect a modest computer.
The only thing I'm in doubt now is wether I'll need to use a 1mm copper plate or not. I've read somewhere that someone strongly recommended the use of this plate on a k610 or AMD WX... GPU in order to keep low temps. I don't know if this is the case with the k1100m. Would anyone with experience advise me about this?
Other than that I already know I will need to flash a new bios to get brightness and boot picker, install macs fan control to manually set fan speed to the ODD (or use the sensor mod suggestion), install oclp to upgrade macOS to the latest version and got everything ready for it.
Any other useful advice will be much appreciated. By the way, I live in a city where the average ambient is above 30ºC most of the year, topping >43º in summer. This iMac already burned 2 ATI 4670 stock GPUs.
 
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