I work on VR systems, where latency is of paramount concern. There is definitely a big difference between consciously noticeable latency and latency that has a

I work on VR systems, where latency is of paramount concern. There is definitely a big difference between consciously noticeable latency and latency that has an effect on people. Yes, to get to the point where a person can notice that latency is occurring and can call it out, you need to be in the 100ms range. But if you want to make a VR system that doesn't make most people physically ill, you have to get "motion-to-photon" latency down to around 13ms (75hz). Even at that range, you still get a relatively large portion of people experiencing issues; I'd estimate 20%. At 90hz, you can get that down to about 10%. At 120hz (less than 9ms!), I haven't seen specific numbers, but my gut feeling from my own work with users is that it's lower enough to care about the extra work to hit that target. I suspect that we can't be fast enough on this issue, that 240hz, maybe even 1000hz, will be necessary to get down to 1%. Luckily, most VR systems today have asynchronous reprojection systems to decouple view movements from application updates (to a degree). It is an extrapolation system, so there are some artifacts, especially around the edges of objects, especially if there is a huge difference between application update rate and view update rate. But I've seen applications running updates at 30fps, which should be headache inducing for sure for the vast majority of people, but they're running on headsets with a 120hz refresh rate and all you really notice are that animated objects look a little choppy.