Use 1 of 2 GPU's to run MacOS

[IanMealworm]

Hey all, I have a question to see if this concept is currently something that is possible. I have recently upgraded my graphics card to a AMD RX6700 which is not supported by MacOS. But the card I upgraded from was a RX580 which is still currently supported. I have windows installed on 1 SSD, and macOS installed on another. I was wondering if there was a way to be able to plug both cards into my PC and use the RX6700 for windows since its great for gaming, but have macOS use the RX580 since its supported. Is this something that is possible?

 

[Edhawk]

Possibly, with a correctly configured SSDT-DGPU-Disable.aml table created for the RX 6700, so it isn't enabled in macOS. A similar SSDT was previously used to disable Nvidia discrete GPU's. I see no reason why it can't be used, given the correct configuration, for an incompatible AMD dGPU. See the link below for how to create and configure the SSDT. Just replace the Nvidia/laptop references and replace them with AMD desktop info.

Disabling desktops unsupported GPUs(SSDT-GPU-DISABLE) | Getting Started With ACPI

Would mean having your monitor connected to both discrete GPU's, but having to swap display-in connectors on the monitor when you want to boot macOS or Windows.

The alternative is to manually unplug the cable in the back of the PC case from one GPU to the other or the car of the monitor, neither of which would be ideal. As there is then the danger of damaging the cable, monitor display-in or one/both dGPU's due to repeat removal and insertion of the DP or HDMI cable.

 

[IanMealworm]

Possibly, with a correctly configured SSDT-DGPU-Disable.aml table created for the RX 6700, so it isn't enabled in macOS. A similar SSDT was previously used to disable Nvidia discrete GPU's. I see no reason why it can't be used, given the correct configuration, for an incompatible AMD dGPU. See the link below for how to create and configure the SSDT. Just replace the Nvidia/laptop references and replace them with AMD desktop info.

Disabling desktops unsupported GPUs(SSDT-GPU-DISABLE) | Getting Started With ACPI

Would mean having your monitor connected to both discrete GPU's, but having to swap display-in connectors on the monitor when you want to boot macOS or Windows.

The alternative is to manually unplug the cable in the back of the PC case from one GPU to the other or the car of the monitor, neither of which would be ideal. As there is then the danger of damaging the cable, monitor display-in or one/both dGPU's due to repeat removal and insertion of the DP or HDMI cable.

I will see about giving this a try and let you know how it goes!

 

[clover84]

Also keep in mind, @IanMealworm that the disabled GPU will still be powered on, producing idle heat and consuming energy.