Huzzah!
Just completed a similar build. Used this success and other very similar ones to guide me (thanks a million, everyone!) I've been building Hackintosh since Lion and this was the most difficult, in some ways. And the easiest! Long story short, once I got smart and bought parts from the recommended lists here, it worked like a champ. Before that, my usual strategy of sorta shoehorning things into a hack really failed me. I think, with High Sierra, we've reached a staggering level of complexity within the Mac OS. (It used to be so easy and fun!) I shall now defer to the experts here when I attempt the next build and stick to the script. Unfortunately, gone are the days when I see some old PC/laptop and think, "Heck, I am going to make a Mac out of that!" I can say, sadly, that it is pretty daunting affair at present. I am not sure High Sierra lends itself to easy builds with old hardware, unlike previous iterations of OSX.
Anyway, here are my basics:
- Fresh install
- iMac 18,2
- Used the latest version of High Sierra 10.13.4 (Version 13.4.9, May 27, 2018 build)
- Used BIOS settings indicated on the first post of this thread
- Followed basic installation instructions found on this site for High Sierra
- Didn't convert to APFS!
- Used AORUS (Gigabyte) RX-580 (8GB) throughout entire install process (no onboard video switcheroo funny business)
Hardly anything to sweat over, here, folks. Just plug in and play by the rules.
Much different than my previous attempts of yesterday and the day before with an MSI Mortar Z370M mobo and XFX RX-560 4GB GPU, which produced nothing but swearing and boot loops. (And
TRULY random behavior. It was surreal; sometimes the installer would almost sorta work, then sometimes it would crash and burn almost instantly, throwing horrific errors and KPs. So frustrating. I about gave up and bought an iMac. Ha!) I figured an MSI Z370 was an MSI Z370; how could they be too different? Same for RX-560...they are about all the same, right? Wrong. People report success with Gigabyte but maybe not XFX. Hrm. (BTW, the XFX would NOT allow me to flash its BIOS using ATIflash to a reference RX-560 ROM as described elsewhere. Go figure. Had it, the XFX probably would have booted, I'd guess.)
In retrospect, it was likely the cursed GPU as the MSI board looked pretty solid. I'll be keeping my eye on others who try this part. It is a nice motherboard! Ultimately, I got fed up and upgraded to a big boy video card and also got a proven motherboard. Only weirdness after I hardwared up was that I could not run the installer (upon booting the second time via USB to finish installation) unless I injected ATI. Weird. And only once. After installation, it was totally fine. Otherwise, it was pretty smooth sailing. The TP-Link WiFi is killer! Plug and play. I am able to see my DRM Apple Music video now. Nice! Onboard sound doesn't work but I haven't fussed with it at all and probably never will. I use a really nice outboard USB AD/DA sound interface for music production, anyhow. I am going to get redundant hardware and clone this puppy right away so I can use one just like it at work!
FWIW, this thing is so fast, I have no inclination to overclock it at the moment.
MY HARDWARE SPECIFICATIONS
MOBO: Gigabyte Z370 HD3 rev.1
CPU: i5-8600K (unlocked hexacore 3.6 GHz)
CPU Cooler: Enermax ETS-N30R-HE
GPU: AORUS (Gigabyte) Radeon RX-580 8GB
RAM: 4x8 GB Patriot Viper DDR4 (PC4-21300 2666MHz, 16GB Kit x 2)
SSD: Samsung 970 EVO NVMe M.2 500GB (Mac OS system/boot volume)
SSD: Samsung 850 EVO 1 TB (File storage volume)
SSD: Samsung 860 EVO 1 TB (Windows 10 system volume)
WiFi: TP-LINK Archer T9E AC1900 PCIe
Case: NZXT S340 Glossy White Midtower Steel