<< Solved >> Disable RX 6700 Xt - Dual AMD GPU setup

[thenemesisdk]

Hi, all.

I recently got my hands on a RX 6700 XT, i know it is not supported, but hope it will soon.
I also have a RX 580 which run great in Big sur.

I have both cards installed and connected both to the same monitor, and switch between graphics card depending if i boot to Big Sur or Windows 10.

My problem is that sleep is not working in Big sur, and i suspect it is because of the unsupported GPU, and i am trying to disable the rx6700xt in big sur, but have noget found a working solution.

I have tried

Disabling GPU | OpenCore Install Guide

Both the SSDT solution and the deviceproperty solution, and some other SSDT but no luck
The closest reaction i got was a reboot using attached SSDT.

ACPI from windows is
PCIROOT(0)#PCI(1B04)#PCI(0000)#PCI(0000)#PCI(0000)
ACPI(SB)#ACPI(PCI0)#ACPI(RP21)#ACPI(PXSX)#PCI(0000)#PCI(0000) ACPI(SB)#ACPI(USBX)#ACPI(RP21)#ACPI(PXSX)#PCI(0000)#PCI(0000)

I use opencore v 0.67

I am running out of ideas, so hope someone is able to help.

 

[Edhawk]

Try this SSDT-DDGPU-RX6700.aml. This should hopefully disable the RX 6700 XT specifically.

It may need editing to make it so the RX 6700 XT is only disabled in macOS, so I have attached a copy of the disassembled and compiled versions of the SSDT.

It is based on Rehabman's SSDT-DDGPU, but has been edited to use the ACPI address you provided above for your RX 6700 XT.

Remember to remove the SSDT-GPU-Disable.aml from your /OC/ACPI folder and the config.plist. Then add the new SSDT to the /OC/ACPI folder and a corresponding entry in the config.plist.

 

[ctek]

Have you been able to reproduce the sleep issue with the 6700 physically removed from the pcie slot? Guessing not, but sleep issues can come from many places.

 

[thenemesisdk]

Have you been able to reproduce the sleep issue with the 6700 physically removed from the pcie slot? Guessing not, but sleep issues can come from many places.

it worked before i installed the rx 6700 XT so i am pretty sure that is the problem. but yes i know there can be a lot of reasons for sleep not to work. But thanks for the suggestion.

 

[thenemesisdk]

Try this SSDT-DDGPU-RX6700.aml. This should hopefully disable the RX 6700 XT specifically.

It may need editing to make it so the RX 6700 XT is only disabled in macOS, so I have attached a copy of the disassembled and compiled versions of the SSDT.

It is based on Rehabman's SSDT-DDGPU, but has been edited to use the ACPI address you provided above for your RX 6700 XT.

Remember to remove the SSDT-GPU-Disable.aml from your /OC/ACPI folder and the config.plist. Then add the new SSDT to the /OC/ACPI folder and a corresponding entry in the config.plist.

Thanks for the file, i tried to load the file, but the card is stil enabled in Mac OS.
i attached the config, i think everything should be okay.

 

[Edhawk]

The ACPI-address in the SSDT is not correct for your system. According to your Hackintool > PCI tab the correct address is as follows:

(_sb.PCI0.RP21.PXSX.GFX1)​

As your Nvidia RX 6700 XT card is located in slot-2, and your RX 580 is in slot-1 which will have the GFX0 address.

Try the SSDT attached, it should have the correct ACPI-address now.

 

[Edhawk]

Sorry, confusing myself and probably anyone else reading this thread, by calling your RX 6700 XT card an Nvidia card in the post above.

The ACPI address for the RX 6700 XT is correct in the SSDT provided in post #6.

 

[thenemesisdk]

The ACPI-address in the SSDT is not correct for your system. According to your Hackintool > PCI tab the correct address is as follows:

(_sb.PCI0.RP21.PXSX.GFX1)​

As your Nvidia RX 6700 XT card is located in slot-2, and your RX 580 is in slot-1 which will have the GFX0 address.

Try the SSDT attached, it should have the correct ACPI-address now.

Thanks for the reply, it is still appearing in mac os, so it still not working, i tried some other SSDT files with the same address, but with no succes.

Im not sure i am during anything wrong, saving the file in maciASL as Machine language(.aml) in EFI->OC->ACPI and adding it to the config using snapshot with propertree.

I only gotten some random kernel panics.

 

[Edhawk]

That's a pity. I'm not sure what else to suggest.

Sounds like you are using the correct procedure when changing or adding a new SSDT.

Yeah, some SSDT's can result in a kernel panic, its not alway clear why they cause the KP.

 

[Edhawk]

I have been looking through a few other SSDT's that are used to disable a GPU. I think I may have added an unnecessary device name to the SSDT I provided above in post #6.

Try this SSDT and see what if anything it changes.