Extreme Framerate Variation in VR, 10fps to 90fps and back

User Support Hub Virtual Reality (VR)
,
1

I got a new computer recently, RTX 4090, Ryzen 9 7900X, 64GB RAM. It should run MSFS very well, including in VR. What instead happens is that the framerate is insanely bad to the point of being unplayable most of the time, but it will sometimes hit 90fps for 1-2 seconds before dropping back down.
I hesitate to even call it a stutter because it seems more extreme than that. As a test I took the headset off and placed it on my desk, completely stationary, looking at the inside of a Cessna 172 cockpit at a small airport, graphics settings on VR default (mostly medium). It will hit 80-90 fps for about half a second, then drop down to 10-20 for a couple seconds, and then repeat. Sometimes if I leave it still for long enough it will actually stay at 90fps until I move the headset at all, then it will start the process over.
I’ve had the developer mode fps display on and I’ve seen it momentarily hit >400ms for mainthread when the frame drops start.
I’ve tried disabling all online streaming aspects, photogrammetry, traffic etc, it seems to be independent of graphics settings altogether. It’s also a fresh install of msfs because it’s a new computer. Other games run as expected, I’ve been playing DCS in VR for example and it runs pretty well. Oh and also I’m on Windows 11…

Here’s a recording of the problem.

Here’s an example of hitting 90 fps for about 5 seconds until I move the headset.

2

A couple of quick ideas:

  • If you haven’t already, put your Nvidia power management settings to ‘Maximum Performance’ for MSFS just to get that out to the way, in case the card is automatically underclocking or something.

  • Use something like Resplendence Software - LatencyMon: suitability checker for real-time audio and other tasks to see if something is periodically busy on your system. It’s a tool used for recording real-time audio, but it’s also a quick way to see if something is running in the background that halts other things.

Good luck!

3

I’ve been tweaking a bunch of settings, lots of things improved it somewhat, especially turning LOD down, but the problem was always stutters when moving the camera, but I finally figured out that it was the stupid Windows 11 HAGS (Hardware Accelerated GPU Scheduling), after turning that off I have absolutely 0 stutters. I’m sure this setting has been mentioned elsewhere and I probably should have seen it earlier, but I figure I’ll leave this here for posterity.

1 Like
4

Yeah, its funny. For every person swearing that HAGS on is amazing, there is another one claiming its rubbish/does nothing. I am in the “does nothing” camp so leave it off. I play VR so couldnt care less about frame generation. I have frame generation VR style anyway which is called “Motion Smoothing”. Thats bacially frame generation. Anomolies are more obvious in VR because its stereoscopic. DLSS 3 has anomolies in its frame generation also but less obvious when not stereo.