Help Spoofing Radeon PRO WX 3200 4GB (640 Shaders) Vs Radeon RX 550 4GB (640 Shaders)

[zzmadd]

Hi all,


I need a little help to understand if the Radeon PRO WX 3200 4GB can have H264 video acceleration.

The Story:
- Some time ago I bought a Veneida Radeon RX 550 4GB (640 shaders) from China.
If I run this card without spoofing I get a 4/3 aspect ratio, no driver loading, no H264 acceleration.
When I spoof this video card using these settings I get video driver loading, H264 hardware acceleration:
Device: PciRoot(0x0)/Pci(0x1,0x0)/Pci(0x0,0x0)
device-id FF670000
revision-id C7000000
subsystem-id 040B0000
vendor-id 02100000
Once loaded these settings this card has video acceleration working without issues. The video driver loads, H264 encoding works with no issues (Final Cut Pro, Handbrake, etc) even on SMBIOS iMacPro1,1, which is what I'm looking for.

- Recently I bought a Radeon PRO WX 3200 4GB (640 shaders) from Dell.
If I run this card without spoofing it I get a 4/3 aspect ratio, no driver loading, no H264 acceleration.
When I spoof this video card using the aforementioned settings, or other Polaris settings like the device ID of the RX560/RX570/RX580, I get video driver loading, BUT NO H264 hardware acceleration:
If I couple this video card with a CPU that has iGPU and I enable iGPU, I get a perfect match. iGPU does the H264 hardware acceleration, the video card does the rest. Final Cut Pro renders with the expected times, Handbrake has VideoToolBox running correctly.
If I couple this video card with a CPU that DOESN'T have iGPU THEN I NO LONGER have H264 hardware acceleration (Final Cut Pro, Handbrake), while the video driver is correctly loaded and the 4GB DDR5 memory is correctly seen.
System Report (see attachment 1) reports "Supported" for Metal BUT it doesn't specify this: "feature set macOS GPUFamily2 v1" or similar.

I thought the two video cards, the RX 550 640 shaders and the WX 3200 640 shaders, fundamentally used the same silicon, BUT I'm not sure about it anymore.
I tested the same settings on Mojave, Catalina, Big Sur on 3 different hardware setup. No difference. When there's a missing iGPU you get "Supported" in Metal BUT H264 hardware acceleration is missing.

Do you think it's a matter of spoofing it correctly, or the WX 3200 (640 shaders) is a totally different video card from the RX 550 (640 shaders) hence it's not possible to have H264 hardware acceleration working?

Any help is welcome.
Thanks a lot!!

PS: I attach a bunch of other things like IOReg of GFX0
@CaseySJ

 

[backwardmac]

Hi zzmadd, you probably need to use an symbiose which is not using IGPU in real Mac. Like iMac Pro or Mac Pro.

 

[zzmadd]

Hi zzmadd, you probably need to use an symbiose which is not using IGPU in real Mac. Like iMac Pro or Mac Pro.

I already do that.
That's precisely the issue. If I use SMBIOS iMacPro1,1 I GET NO H264 acceleration with the WX 3200.