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AMD RX580: Need Help Post-Install Big Sur OC 0.6.4

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Hi,  I'm new to this forum, and need some help.


I have a working 0.6.4 Big Sur install, and I'm trying to get the boot selector GUI to work properly. It works, but I have not been able to get the display resolution to work properly.  I can make it work in either huge graphics (very low res) or in a better but still big but awkward resolution (things are stretched sideways).


I have an RX580 graphics card and need to have my iGPU disabled (Iris Pro 6200 of i7-5775c CPU), otherwise the system will not boot.

There are various settings in the config.plist I have tried, but nothing works well.  I have tried a lot of combinations.

I have set the following device property in order for it to work in the weird wide resolution:

  • PciRoot(0x0)/Pci(0x2,0x0): AAPL,ig-platform-id = 04001204  (this should mean the gpu is not driving the display)


The rest is per OC guide for Opencanopy


resolution == > max etc etc.

What am I doing wrong ??


I have also tried giving it a given resolution, say 2560x1440@60, but it won't recognize any numeric setting, not even 1920x1080@60.



Hello Hervé,


Thanks for the reply.  As things stand I have a SMBIOS for an iMac15,1.  I will try it as an iMac16,2


The guide I followed was for Haswell/Broadwell, I will try Haswell-E also instead, see how that goes.  I agree both the iGPU and dGPU should be supported.


My setup is:


Gigabyte z97x-Gaming 7

RX 580 8Gb

32 Gb Ram


BTW I never meant the framebuffer setting would not drive the display I simply took that setting from the Haswell Dortania guide:


"AAPL,ig-platform-id    Comment
0300220D    Used when the Desktop Haswell iGPU is used to drive a display
04001204    Used when the Desktop Haswell iGPU is only used for computing tasks and doesn't drive a display
07002216    Used when the Desktop Broadwell iGPU"


Due to the fact that I had to turn the iGPU off, I thought this was the better setting option.  I did try 07002216, with no result, endless reboot and weird resolution, it reboots once the Apple logo shows up.  At least that setting 04001204 booted.


I chose Haswell/Broadwell guide instead of Haswell-E guide because the guide for Haswell-E assumes the CPUs don't have an iGPU :


"By default, the Sample.plist has this section set for iGPU and Audio. We have no iGPU so PciRoot PciRoot(0x0)/Pci(0x2,0x0) can be removed from Add section. For audio we'll be setting the layout in the boot-args section, so removal of PciRoot(0x0)/Pci(0x1b,0x0) is also recommended from both Add and Block sections."


So based on that, and considering the Haswell/Broadwell guide did mention the existence of my iGPU (07002216), I went with that guide.


I will try a mish-mash of both guides, Haswell-E guide throughout, but with iGPU setting using 07002216 taken from the device properties in the Haswell/Broadwell guide.


Please let me know if you have any thoughts or comments.


Thanks again,





I just finished updating a few things, now SMBIOS is iMac16,2, 07002216 for iGPU, and I can boot while having both GPUs but still no cigar on the resolution.  I can't change it from UEFI - Output in the config.plist

I am attaching a zip of config.plist, as all efi is over the 10mb limit, any help would be very welcome.  This is the last bit for an otherwise very good and stable install.






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