After wasting time........no tinkering
I finally got this working.
I only modified the iMac version as you can't use a RX 5700 XT on a iMac 14,1 apparently.
Also it is annoying the drop of 32bit support but I would rather just run these on an older Mac. Like my old iMac with only support for El Captain.
I am currently using a USB headset but will probably need to install LILU and a sound kext at some stage. I did not install whatevergreen but it does look promising for some builds.
All my previous builds were mostly on Gigabyte and Asrock Boards seem to work best with minimal fuss.
Everything else works out of the box. I finally worked out to install the latest Clover to BIOS first then reinstall to UEFI EFI with APFS. Then it worked. It would not work any other way with this board just in case anyone else tries this one. I'm using Clover v2.5K r5101.
Motherboard Asrock H81M-HDS (Very basic Motherboard) No UEFI selection in BIOS. Only in Boot menu.
It eventually finds the EFI partition without interaction with above Clover install method.
i7-4770
HP RAM 16GB (2x8)
Western Digital 1TB SSD
MSI RX 5700 XT MECH 8GB
I originally purchased the 5700xt to go with my W10 computer, but it was worse than my GTX1080. So here it is
Also yes it does throttle with this board and CPU but it's only a tinker toy not a main rig so the parts will most likely end up elsewhere
Normally I would just use Windows or Linux these days but I thought I needed something to do.....
Thank You for keeping this site updated and all the hard work you do here at tonymacx86 dot com.
UPDATE: So I finally worked out that mbr with ss with clover from the source forge clover page that is in a post here on the main page works with APFS on this board without the need for UEFI. Also Vanilla made usb made with terminal works on this board. Unibeast is awesome for some boards but sometimes different methods work and others don't. So I put a RX570 in this and found that with file vault tuned on I got a black screen. Loaded with Intel graphics turned File Vault off and switched to RX570 card and it worked natively no issues. I really miss my 32bit games in my game stores so I did do a fresh install of MOJAVE and again turned off File Vault to get the RX570 graphics working without a black screen. I did not use LILO,WEG and the only KEXT I used was the 8111 v2 to get ethernet. Hope this helps out someone.
CHEERS