Threadripper GPU passthrough not working

What is the story on Threadripper and PCI passthrough? Is it broken, bugs??? I am not any luck trying to pass my rx480 or my gtx1080 through. Wendell’s video and advise made it seem like it was working but it doesn’t seem to be the case.

if you watched the latest video where he talks about the lian li standing desk he talks about how its not there yet but hes working with asus i think or MSI their engineers to get it working with bios updates

System won’t even boot now