It turns out this is an Nvidia problem. The 1080’s Displayport does not work with the Vive currently. I was told by Nvidia that this issue is “currently being looked into” and it will be fixed in the next driver release, although they would not give me a time frame when I asked. Quite frustrating when you spend $700+ on a GPU for VR as its main purpose and it cannot even work with one of the two main VR headsets. Such is life I guess.