I was having trouble with PHOTOS hanging when trying to encode video uploaded from my DSLR. The following Kexts and changes to my config.plist fixed my problem. It also seriously enhanced my bruce test to 15 secs and h264 export times. Basically it allows the RX580 card to work with the internal graphics on the mother board
I installed the following kexts to EFI/CLOVER/kexts/Other in my EFI :
Shiki, Lilu, IntelGraphicsFixup, Whatevergreen
from Rehabman's FAKEPCIID:
FakePCIID.kext and FakePCIID_Intel_HD_Graphics.kext
I made the following changes to config.plist in clover:
In System Parameters verify Inject Kexts is set to Yes
In Boot page add Custom Flags:
shikigva=4
-rad4200
click -disablegfxfirmware
In Devices tab:
Set INTELGFX box to 0x59128086
Set ig-platform-id to 0x59120003
In Acip tab: under DSDT patches (order is important)
change HECI to IMEI: find 48454349 Replace 494d4549
change GFX0 to IGPU: find 47465830 replace 49475055
change PEPG to GFX0: find 50454750 replace 47465830
Bios changes:
Integrated Graphics: Enabled
DVMT Pre-Allocated: 128M
Initial Display Output: PCIe 1