Mac Mini (2018) + eGPU + Dell UP3218K
I've been lurking around the net and haven't found anyone got the Dell 8K working on MacOS, any idea guys? Hardware-wise seems like the recent existing eGPU builds (including the new Blackmagic eGPU Pro with Vega 56) technically support it, it's just the OS. I've seen people getting two 4K screens show up on the 8K.
While the Blackmagic Pro has a single DisplayPort 1.4 port, its specification page states a max resolution output of 5K @ 60 Hz. If you're planning on adding an 8K monitor, I'd recommend using a modular eGPU setup with standard graphics cards.
The UP3218K requires two DisplayPort 1.4 inputs to get 8K 60Hz. A single connection may be able to support 8K 30Hz. With the Blackmagic eGPU Pro, you would use the other Thunderbolt 3 port for the second DisplayPort 1.4 input (using a Moshi USB-C to DisplayPort cable). I don't know if macOS supports dual link SST DisplayPort 1.4 displays though. It does support dual link SST DisplayPort 1.2 displays (like the LG UltraFine 5K or the Dell UP2715K). Windows won't have a problem with 8K 60Hz but I don't know if the Blackmagic eGPU Pro will work with Windows. Other eGPUs should be ok.
That's the thing, I haven't found any resource on MacOS support for 8K ...
I think at least DisplayPort 1.4 is working with DisplayPort 1.4 5K displays like the new LG 34WK95U-W? If that's the case, then at least 8K 30Hz should work or it would probably be a simple fix (like the pixel clock patch). If that works, then dual link SST DisplayPort 1.4 should be another simple fix if it's implemented similar to displays that use dual link SST DisplayPort 1.2.