Meant to be Seen

Hello gentlemen! It would help me a great deal if some of you knowledgeable folk could answer a couple of questions and provide any additional details you think might be useful.

What type of v-sync can we expect to be common in upcoming VR systems from valve/htc, facebook and razer? Will it be g-sync, FreeSync, both, old fashioned normal v-sync or something else?

I believe oculus rift can work with a 60 fps input and 90 fps is only suggested to avoid sickness, is that correct?

What will be the refresh rates for some of the upcoming VR devices i mentioned above? I think the oculus rift will be 90hz but is it likely to support other refresh rates as well?

If you don't have much to say regarding my questions then feel free to add any information you know about these devices and their refresh rates and v-sync capabilities.

Thanks in advance!

Well, the DK2 uses pretty much normal V-Sync, but with software tricks to get lower latency or a smoother image. In this case the refresh is 75Hz, but time-warp allows for smoother head-movement even at lower frame-rates.

Sony is doing something similar with a box that does reprojection and upsampling of refresh. Basically you could code a game for PS4 to run at 60fps, but it would run on the headset at 120Hz.