Hi, I finally built my iMacPro based on KGP's excellent guide. It's a bit disappointing because I have nothing more to report than it works perfectly. The little difficulties I ran into were with the EKWB reservoir that was really hard to stop leaking, just had to be overly tight. Hurt my hands doing that and they're big mits. Struggled a bit preventing 10.3 from absolutely insisting that my system drive be apfs which I am absolutely not having. Kontakt my main tool doesn't work with that file system and I've heard of other apfs weirdness. But typing 'avoid apfs' showed me an easy way round. Had to clear the cmos after upgrading the bios and it took me a while to figure out that profiles were saved under overclocking. OS X offered an upgrade with the same number that went fine.
Next step will be figuring out how to implement my PCI cards and getting the SSDT straightened out in IASL and IOREG but after having read it twice it just gave me a headache so I'll try another day. I was worried about finding the right overclock but I just went with KGP's bios settings and left CPU core voltage on auto. I did not experience any weirdness as described in that section of the bios settings and everything clocks just perfect. I get a 58000 Multiscore and a 5600 single with temps in the 70°max. This is ideal for me as I don't want to delid my cpu and with two cores less than a 7980Xe a lower score is to be expected. The fully native HWP is really impressive and the water cooling really tracks the temperature immediately. I put my radiator on CPU fan header and the pump on the CPU opt header.
As I said earlier everything works boringly well. Sleep, Shut down, USB, native NvME (blazing fast), the RX580 , the two Lan ports, the overclocking, the memory, Istat menus, HDMI audio, the cute ImacPro splash screen. I have no use for Wifi, onboard audio or bluetooth so I can't comment on those since they are turned off in the bios. Once I have figured out the ioreg ssdt thing I'll give some feedback on how well it handles my 4 PCI sound cards. With a bit of luck and a PCI riser cable I might even be able to get the thunderbolt card going for a total of 6 pci cards but that's just icing on the cake.
As a comparision my dual Xeon 88core had a 55000 bench but a measly 2400 single which was often a problem as it could hardly turbo at all. The 8700K coffelake rig I built a few weeks ago is more than decent for less than half the price of this imac pro but it's also half the geekbench and dawbench VI score. In my work the convenience of having one rig rather than messing with slaves is well worth the price difference.
Big thanks to KGP for his tremendous effort. I often see weird vibes on this thread which is really unfair when you think that after almost 600 pages he is still hanging in giving advice and making contributions to his original post. It's baffling to me.
As someone who only has a basic hackintosh knowledge he has enabled me to replace my dual xeon 88 core setup with a machine that is much more appropriate for my specific needs in a very professional and throrough way. Honestly without the original post I would never have jumped on this iMacProwagon that requires open loop watercooling an expensive cpu, expensive MB. It's a bit early to say 100% success as I've had issues with PCI cards in the past but so far so good.
