1. Test machines:

-- iMac11,1 A1312 27inch Late2009 (The machine with "Core 2 Duo" processor is iMac 10,1 it can't work)

-- iMac11,2 A1311 21.5inch Mid2010 

-- iMac11,3 A1312 27inch Mid2010

-- iMac12,1 A1311 21.5inch Mid2011

-- iMac12,2 A1312 27inch Mid2011

2. "Which option should I buy?"

- iMac12,2 A1312 27inch Mid2011 with old graphcis AMD HD6970M 1GB / 2GB, must buy a new X-bracket, choose option 2 "Card+X".

- iMac12,2 with other GPUs, and iMac11,1 / 11,2 / 11,3 / 12,1 (original machines), choose option 1 " Card".

- If you are unsure about the model, please contact me before placing an order.

3. Known features:

- Enable GOP VBIOS / ROM

- Boot screen with OpenCore

- Brightness control working

- GPU power management working

- Sleep / wake up working

- Needs High Sierra or better (AMD support)

- Metal supported

- Monterey / Ventura / Sonoma supported

- Windows / Bootcamp supported (EFI)

- VDA decoder "Fully Supported" in iMac12,1 / 12,2, but "Failed" in iMac11,1 / 11,2 / 11,3

4. Known issues with High Sierra

- Using High Sierra the GOP vBIOS disables the internal LCD on power on (75% loading). There is no software fix for this bug.

- Work around: Use an additional external display on boot.

You can just use a miniDP emulator stick (recommended). You will not get the internal LCD switched on unless you connect an external display to the miniDP ports close to the earthnet ports.

5. How to assemble?

- The GPU is flat, does barely get into contact with the copper part of the heatsink and needs an additional copper plate to bridge this gap (size 15mm x 15mm x 0.8mm thickness), I will ship the copper with card. Check visually after premounting it using a light. Put it directly on the GPU using thermal paste on both sides to guarantee optimal heat transfer from the GPU to the copper plate and down to the heat sink.

-If you have a no-power situation, mask off the exposed capacitors on the card to avoid shorts when installing the GPU to heatsink.

- Recommand 2 pipe heat sink （35w and 50w), mask off the exposed capacitors on the card to avoid shorts.

- If you use the 3 pipe big heat sink (75w from iMac12,2), you need to clean all the old thermal gel, use new thermal gel on VRAMs, and pay more attention on assembly. Contact me for details if you are not clear.

6. How to install ?

Case 1: The old GPU died.

1). Use my EFI directly.

2). Contact me for the EFI files and user manual after placing order.

Case 2: The old graphics still work, and you know how to configure OpenCore.

If you know nothing about OpenCore, go back to Case 1 and use my EFI directly.

1). Pre-install OCLP (OpenCore-Legacy-Patcher) - run OCLP to build and install new OpenCore to SSD EFI partition. ( No OpenCore, no working!)

2). Change the graphics to WX 4150, reset PRAM to make the new EFI works as default boot.

PS: MacOS recognizes this card as "AMD Radeon Polaris", but Hackintool recognizes the correct model "Radeon Pro WX 4150". You can add the model in config.plist if you want MacOS to recognize it as "WX 4150".