iMac 5K i9-9900K, Radeon Pro 580X, 48GB memory, external SSD for games via USB-3 and Win 10 on Bootcamp
Hardware pictures to follow
I am using internal iMac screen.
I am new here so I can not post images - so here are all benchmarks and tech data:
1. Install Windows via bootcamp, keep eGPU switched off. Just downloaded latest Windows ISO from Microsoft
2. Install bootcamp drivers automatically
3. no DDU/other tweaks are needed, switched off Windows Update
4. put egpu into sonnet box. Note that this is tough to insert as part of GPU will really touch the Sonnet Box as you try to insert it,
but it is possible.
5. Windows will detect NVIDIA but would not install proper drivers
6. Install NVidia drivers 497.29
7. then Reboot and you will see in Display Adapter NVIDIA with exclamation and error 43.
8. Then disable 580X and reboot (note that you will have to do it each time you shut down windows)
9. after reboot you will see NVIDIA working and iMac will switch to 4K
otherwise you will face Code 43 again. so I am using USB-C for my external SSD for gaming.
All benchmarks on internal monitor as I do not have external monitor.
It can generally handle 4K in modern games at 40-60fps. Going one stop down from 4K will always give you 60fps.
Ray Tracing and DSS generally have 5-10FPS hit depending on the game.
what is weird is that GPU in most cases will only get to 60-70% load max.
I initially thought that this is TB3 limitation, but then on some modern games like Tomb Raider, Cyberpunk it easily gets to 100%.
Another weird thing is that there are occasional freezes during games, trying to work it out as it happens when my SSD load gets to 100% for some reason.
More updates soon
@john3bet, Thank you for sharing this build. Looking forward to seeing your experience with loopback eGPU mode on the iMac. Many apps and games do not have good optimization for eGPU mode so often time you don't see full 100% load.