Disabling GPU

GPU Spoof

So you need to hide your unsupported GPU? Well with OpenCore things are slightly different, specifically that we need to specify to which exact device we want to spoof. There are 3 ways we can do this:

  • Boot Flag

    • Disables all GPUs except the iGPU

  • DeviceProperties

    • Disables GPU on a per-slot basis

  • SSDT

    • Disables GPU on a per-slot basis

Boot Flag

By far the simplest way, all you need to do is add the following boot-arg:

-wegnoegpu

Do note that this will disable all GPUs excluding the iGPU

DevicePropeties Method

Here is quite simple, find the PCI route with gfxutil and then create a new DeviceProperties section with your spoof:

path/to/gfxutil -f GFX0

And the output will result in something similar:

DevicePath = PciRoot(0x0)/Pci(0x1,0x0)/Pci(0x0,0x0)/Pci(0x0,0x0)/Pci(0x0,0x0)

With this, navigate towards Root -> DeviceProperties -> Add and add your PCI route with the following properties:

Key

Type

Value

name

data

23646973706C6179

IOName

string

#display

class-code

data

FFFFFFFF

SSDT Method

There are many ways to find the path but generally, the easiest way is to get into Device Manager under windows and find the PCI path.

Example of device path:

\_SB.PCI0.PEG0.PEGP

DefinitionBlock ("", "SSDT", 2, "hack", "spoof", 0)
{
Method(_SB.PCI0.PEG0.PEGP._DSM, 4)
{
If (_OSI ("Darwin"))
{
If (!Arg2) { Return (Buffer() { 0x03 } ) }
Return (Package()
{
"name", Buffer() { "#display" },
"IOName", "#display",
"class-code", Buffer() { 0xFF, 0xFF, 0xFF, 0xFF },
"vendor-id", Buffer() { 0xFF, 0xFF, 0, 0 },
"device-id", Buffer() { 0xFF, 0xFF, 0, 0 },
})
}
}
}

What this SSDT does special compared to Rehabman's SSDT is that this adds the If (_OSI ("Darwin")){} block so that this SSDT wouldn't be applied when booting other operating systems

Fixing Windows

So something that many users are annoyed about is the fact that you need to switch between GPU outputs. Well a neat little trick on Windows is that you can reroute your display options to a specific GPU:

Credit to CorpNewt for image