Enabling igpu alongside RX580 for better Handbrake performance

[miliuco]

Many thanks for your replies. Can I ask why I need to change to SMBIOS imac19,1? When I was creating this hackintosh and decided to do it as a Big Sur rather than Catalina, it refused to install when I had the machine set as iMac19,1 (OS cannot be installed on this platform) and installed Ok when I set it to iMac18,3?
Thanks

Make one more try with iMac19,1, without changing anything else except adding in boot args this: -no_compat_check and tell me if it works. It's an OpenCore option that I don't know if it also exists in Clover, what bootloader do you use?

 

[m0rb1u5]

Opencore 0.6.3

 

[miliuco]

Opencore 0.6.3

Then make a try.

 

[m0rb1u5]

Would you mind summarising the steps? Sorry to ask but I am a bit of a noob despite getting this system up and running OK - I used an app to make my EFI and followed instructions found around for the Kexts and SSDT's I needed and don't have a great deal of expertise on making tweaks!

 

[miliuco]

Would you mind summarising the steps? Sorry to ask but I am a bit of a noob despite getting this system up and running OK - I used an app to make my EFI and followed instructions found around for the Kexts and SSDT's I needed and don't have a great deal of expertise on making tweaks!

Ok. Can you upload here your EFI folder as ZIP so that I can study it? After seeing it I can give you comments and instructions.

 

[m0rb1u5]

Sure thing. Gimme a minute. Appreciate your time!

 

[m0rb1u5]

Sorry, took ages.

 

[miliuco]

Sorry, took ages.

Ok, I got it, let me look inside.

 

[miliuco]

Sorry, took ages.

I have made these changes:

• Updated to OpenCore 0.6.4.
• I have added SSDT-USBW.aml / USBWakeFixup.kext / DeviceProperties - PciRoot (0x0) / Pci (0x14,0x0) - acpi-wake-type=01 to improve sleep output from USB keyboard or mouse.
• In DeviceProperties you have for the audio layout-id=1, I remove alcid=1 from boot args which is redundant.
• In DeviceProperties - PciRoot (0x0) / Pci (0x2,0x0) - AAPL,ig-platform-id I have added the value 0300913E so that the iGPU works in headless mode.

I attach 2 EFI with different config.plist files, one for iMac19,1 and one for iMacPro1,1, remember to rename to config.plist when you test them. I have changed the serial numbers to be suitable for each Mac model, the ones you used in iMac18,2 are not valid for these SMBIOS.

For iMac19,1 you must have the iGPU ENABLED in BIOS, for iMacPro1,1 you must have the iGPU DISABLED in BIOS. Every time you try a different EFI, do ResetNVRAM the first time you boot with the new one.

Just in case, review BIOS settings, I only write down the significant options, there are many other options that do not influence macOS and that you can configure to your liking (for example the LEDs on the board, etc.).

• XMP Profile: Auto / Profile 1 / Enabled (eXtreme Memory Profile, I use 3200 MHz memory and without this profile it works at 2600) (only if you have 3200 RAM)
• Platform Power Management: Disabled
• VT-d: Disabled> Important
• XHCI Hand-Off: Disabled
• Legacy USB Support: Enabled
• Network Stack: Disabled
• CSM: Disabled> Important
• Secure Boot: Disabled> Important
• Fast Boot: Disabled> Important
• OS Type: Windows 8/10 (not WHQL)
• Wake on LAN: Disabled
• Integrated Graphics: Enabled> Important (iMac19,1)
• Integrated Graphics: Disabled> Important (iMacPro1,1)
• Initial Display Output: PCIe 1 Slot> Important
• DVMT Pre-Allocated: 256M or higher.

Note: Rename the EFI-imac and EFI-imacpro folders to EFI only when you place them on the EFI partition of the disk.

I have tested the 2 EFIs on my PC, very similar to yours, and both start well and fast, enabling and disabling the iGPU depending on the SMBIOS. Both EFIs show VDADecoder Fully Supported in Hackintool. I hope that in your case they also work well. You must try both and choose the one that works best with video.

 

[m0rb1u5]

Wow thank you very much for your time and effort. I'm back home tomorrow so will give it a go. Again, many thanks!