I have the Vive pro and enjoy watching my movies on it. What sucks is that I can't really share that experience with my girlfriend without having to take turns. Would it be possible to watch the same movie on one pc if i got a second Vive? Not to play games, just watching movies.
Running two HMD off a single consumer-grade PC is not super practical and in many cases not possible. You typically need server grade hardware, a dedicated GPU for each HMD, and you need to be skilled in virtual machines. In almost all use cases, it's always going to be cheaper, far more redundant, and simply more efficient to have 2 sperate VR PC's than trying to drive 2 HMD off a single PC.
Basically you'd need to find a second way to power an HMD for your GF and then you'd likely want to use the app Bigscreen to create a virtual space where you and your GF can watch content. Since you're aiming for just video playback, you can aim for a less powerful HMD and even a standalone HMD as long as it's supported by Bigscreen.
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