How to switch from discrete to CPU graphics?

[naujoks]

I used to have a XT 5700 in my system but now got an Nvidia card.
I'd like to use the CPU graphics of the 9900K for time being. What changes do I need to do to make this work?

 

[naujoks]

I enabled the iGPU and can boot up to the moment when the GUI loads, then the screen goes black and the monitor goes into sleep. The system is fully loaded and working though. (Z390 Aorus Ultra motherboard)

 

[Edhawk]

Have you done all of the following:

1. Removed any AMD specific boot arguments and Device Properties from your config.plist?
2. Changed the IGPU Device Properties from a Headless to a connected Framebuffer?
3. Added the other framebuffer properties necessary when using a connected framebuffer/IGPU?
4. Changed your SMBIOS to reflect you are using a system with just the IGPU present?
5. Disabled the Nvidia DGPU with the following boot argument (-wegnoegpu) or with an SSDT-DDGPU.aml?

If not you have some work to do before you will see your desktop with just the IGPU active in macOS.

I would suggest you have a read of the WhateverGreen FAQ Intel HD page, as it contains a lot of the information you require for your Coffee Lake iGPU to work correctly - https://github.com/acidanthera/WhateverGreen/blob/master/Manual/FAQ.IntelHD.en.md