Substantial DRM lease presentation latency resulting in unusable VR/ HMD experience

Graphics / Linux Linux
4

I have the same issue. There is even a much older thread about people experiencing this since 440.04 here Latency in VR (with GSync) since 440.44

For the time being I have patched monado to use VK_PRESENT_MODE_IMMEDIATE_KHR which seems to “fix” the latency issue at the cost of having tearing in VR with the tearline staying mostly out of my view (better than getting motion sickness…)

Now the question is why there are latency problems with the other presentation modes but not immediate mode. I can think it’s either one of:

  1. Somehow we get a swapchain that is one frame too long (would be consistent with ~11 ms delay I experience)
  2. It’s not the swapchain something about vblank timestamps from the driver that somehow throws the pacing off significantly.

FWIW my patch is available here.
Start Monado with XRT_PRESENT_MODE=0

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