Update - the High Sierra install
Thanks to everyone for their help elsewhere on the forums, I've now taken the plunge and installed High Sierra after watching how easy or hard others were finding it over the last month. Truth is, it wasn't straight-forward as MultiBeast 10 isn't out yet, so I had to take a hybrid approach. But I got there.
My choice was to do a fresh install on a new SSD so that if things went badly I could easily revert to Sierra.
Okay here are the steps I needed to take:
1) Follow the guide
https://www.tonymacx86.com/threads/...ierra-on-any-supported-intel-based-pc.235474/
If, like me, you were keen to try the new Apple file system - APFS - I can only offer my own experiences. I found the new disk ID structure - disk0s1, disk0s2 etc - has been altered. For example my HS SSD was at disk3s1 when I first installed. I expected the EFI partition to therefore be at disk3s0. It was actually at disk2s1 instead. Something to do with a 'Container" used for the APFS system. This might have been why Clover wouldn't install to the ESP and just failed repeatedly. In the end I unmounted any other attached drives and tried again. Still no go. So I decided to go back, re-partition, and start again using the HFS format instead. UniBeast 8 has a special script to allow this on an SSD which is in the thread.
When you get as far as
Step 4, section 9, f in the above, the guide assumes you'll be running MultiBeast 10 next. Because it's not yet released, here's what I did -
Reboot using the UniBeast stick and then choose the drive with the HFS Clover icon and a black Apple label - not any of the others with a High Sierra icon attached. Highlight it and you'll see the name of your destination drive. This is the correct one to complete your install.
Next the system will reboot. Mine gave me a progress-bar with 18-minutes to complete, but immediately rebooted once more; then it soft-booted (black screen with white Apple logo) a couple of times before the installer progress-bar returned and things settled down, finally completing the process.
At the final reboot I chose Safe Mode from the Clover boot Options because I still had my Radeon RX560 in place and figured it wouldn't be recognised yet. Once at the High Sierra desktop (I can confirm not choosing Safe Mode results in a black screen), not much was working at this point - no sound, ethernet or graphics acceleration. So...
2) With no MultiBeast 10 to help, and Clover release 4268 unable to create a new EFI folder tree for me, copying across my old Sierra EFI folder seemed a logical way forward.
For every build I back-up my EFI folder - it's easy and quicker than a full SSD clone (though you should still do this regularly to mitigate any major problems). For me, these back-ups act as a handy restore-points while experimenting. So check your disk ID using
Terminal and
"diskutil list" and then run
EFI_Mounter_v3 to mount the EFI partition. Drag your Sierra EFI back-up into it.
3) For
Ethernet use KextBeast to install the
AtherosE2200E.kext to
Library/Extensions. Again I copied this from my Sierra install, although it is in the MultiBeast package as well (see below).
4) for
Audio - open MultiBeast 9.2.1 using the
Show Package Contents right-click option,
Contents, Resources. Find the
Clover_ALC1220.pkg file and copy it to your desktop. Run it. For me this worked fine with my old Sierra
config.plist. No need to run any extra scripts, this did the job easily. I still have
Internal Speaker output via the green port to my powered desktop speakers AND
HDMI output to my monitor's speakers.
5) for the
Radeon Graphics I copied the latest
Lilu.kext and
WhateverGreen.kext into the HS
EFI/CLOVER/kexts/Other folder, over the older ones already there.
https://github.com/vit9696/Lilu/releases
https://github.com/vit9696/WhateverGreen/releases
I'm still using System Definition iMac14,2.
That's the hardware sorted.
I hadn't signed-in to iCloud during installation and had turned-off my wi-fi to stop any unwanted activations or conflicts until I had the system up and running properly. The serial/board numbers from Sierra were still in there and verified. I didn't want any lock-outs occurring. Once I decide to swap to High Sierra permanently I'll turn-on the wi-fi and log-in.
So in summary, for me the upgrade wasn't exactly straightforward. I'm glad so many others are reporting it's been easy for them, but very many are finding it difficult. Hopefully the work-arounds I've highlighted might help someone with similar hardware.
MultiBeast 10 will reduce the pain you, unfortunately, had to endure. However, MultiBeast 10 has not been a simple upgrade as in the past. The experiences you had are being addressed in MultiBeast.
