How to make lg ultrafine 5k display work with external gpu?

I brought a sonnect Breakaway Box 350 and an amd RX580 video card. I upgraded my macbook pro to macOS high sierra 10.13 beta 5. I plugged the enclosure in my mac and find that there is no way to connect my lg ultrafine 5k display to the video card. So, I plugged the display directly to my mac's thunderbolt 3 port. But it doesn't seem to work. How to make lg ultrafine 5k display work with external gpu?

Replies

I'd love to know if Apple (or LG, or...anyone...) are working on this?

I have my LG ultrafine working with my rMBp early 2013 and Sonnet Breakaway 550 with an upgraded PS650watts & Sapphire RXVega 64. It worked in

10.12.6 & 10.13.3. It also worked with a rMBPr early 2014 (gt750m descrite) for beta 2, but the beta 2 refresh killed it.


Since my 2013 mBPR is only a TB1, I'm using a apple TB1-TB3 adapter. Obviously, both the data rate & power supplied is way low and I'm driving it with the gt650 so the res is only 2560x 1440. I think the key is that I'm first going to a OWC TB3 dock then to the monitor. The Vega 64 still preforms extremely well on benchmarks ~ geekbenck metal ~ 173386 & opengl 163049.