The motherboard has two on-board gigabit Ethernet ports, ideal for 802.3ad LACP link aggregation. One of the ports is natively supported, but the other (Intel i211) requires a modified Smalltree kext, which is also included and applied in post-installation. Note that the Smalltree driver for the i211 Ethernet port does not support 802.3ad link aggregation at this time, but any macOS-compatible add-in or external Gigabit Ethernet port will work in combination with the Intel i219 port. For example, the Gigabit Ethernet port built into the OWC Thunderbolt 3 dock works perfectly in combination with the Intel i219.
Just wanted to note: for the I219-V you still need IntelMausiEthernet.kext, or am I mistaken? (Or did you just write natively supported, because you were going to install the kext anyway?).
Nevertheless, after a long while of lurking, I too managed to set up a build with partial use of your instructions and attachments. For anyone having problems installing on an Aorus Xtreme Z390 I attached my EFI Folder. Worked on 10.3.3 (had to install because of the Aquantia LAN, but did something else entirely in the end, as mentioned in the 10Gbe Support thread. At this point I'd like to express my utmost gratitude to
@pastrychef for his informative thread, which, I believe, was the trigger bumping me into the direction I went) and currently on 10.4.4. Here I'd also like to thank you for sharing your informations (I believe they were utterly necessary for me, since our boards are "almost" identical).
I used the onboard createinstallmedia of OS X to build an installer and used kexts and patches JUST in the EFI folder.
While still having problems reaching the installer, I had the brilliant idea of plugging my HDD into my "old" x58 rig, installed OS X from there and just bothered with booting into it further on.
As far as I can tell everything seems to work fine (except one of my two Wi-Fi Cards, but that's another story entirely, didn't test TB3 and the 10Gbe LAN though, but they are recognised under System Informations).
My current setup goes like:
SMBIOS: iMac18,3 (19,1 won't boot, so, without even doing research my guess is, that you'd need one of the "special"
OS X builds for that one)
MoBo: Aorus Xtreme Z390
CPU: i9-9900K
MEM: 2 x 8GB G.Skill Trident Z Royal Silver (still slotted A1-B1
, waiting for the 16GB modules to arrive in Germany
for further upgrading to 64GB)
Graphics: Sapphire Radeon RX Vega 56 Nitro+ (dude, why u buy 56? Because I in person can't stand heat or too
much light)
PSU: Seasonic Prime Ultra Titanium 850W
Case: Full House Noctua cooled Corsair Dark Base Pro 900 rev2 (I know what you might be thinking, but actually I
chose the case and THEN found out about the prebuilt custom SSDT, though my USB 3.1 port on the case
seems not working, just getting power. Also still have to figure out what to plug in where to make the light
switch work
)
CPU Cooler: EKWB Block, Radiator and Res (Acetal, not plastic) with Mayhems hose and liquid and Bitspower fittings.
Actually funny story, because there was no other cooler I could fit onto a delidded CPU
Wi-Fi: BCM94331 (still a bit jumpy under Windows) in a PCIe x1 adapter (with BCM94360 verbose is stuck at
IO80211Controller start, haven't figured out why, yet, works fine under Windows)