Performance degradation when application in background (VR only)

Bug Reporting Hub Virtual Reality (VR)
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1

ISSUE DESCRIPTION

When MSFS2024 loses focus in VR it gets heavily throttled by windows, resulting in large FPS drops when the GPU spins down. This doesn’t happen when not in VR e.g. you can switch to another application and MSFS2024 maintains performance for any amount of time. This issue didn’t exist in MSFS2020.

FPS usually recovers after around 1-2 minutes when focus returns, however for that time the performance is dreadful. In some worse case scenarios it doesn’t recover at all without a restart.

Worth mentioning that this is happening with all power settings set to maximum performance (Windows power settings, application specific GPU settings in Windows, Nvidia control panel etc)

I’m unsure if this is a Pimax / Nvidia specific issue. It got better after SU4 as it used to almost never recover, but it still can cause quite a few issues.

To sum up the issue:

  • Non-VR mode; MSFS2024 maintains performance and GPU/CPU resources indefinitely when not in focus.
  • VR mode; MSFS2024 loses performance and GPU/CPU resources when not in focus for more than about one minute, and either recovers after around 2 minutes when it regains focus, or doesn’t recover at all without a restart.

As much as I distrust anything AI, ChatGPT had the following to say if it gives any helpful context, particularly the last line (unless it is all nonsense in which case please ignore it…):

    1. MSFS 2024 uses DX12 + OpenXR swapchains
    2. Crystal Light runtime releases desktop focus immediately
    3. Windows assumes the app is idle
    4. This is a known regression with OpenXR-native apps on Windows 11 + RTX 40-series.
    5. This requires Asobo to mark MSFS as “foreground VR application”

FREQUENCY OF ISSUE

Every time, whenever MSFS2024 loses focus for more than around one minute.

REPRODUCTION STEPS

Please list clear steps you took in order to help our test team reproduce the same issue:

  1. Start a flight

  2. Enter VR mode and position camera etc

  3. Switch to another application in Windows, leaving MSFS2024 running in the background (still in VR, but remove headset)

  4. Use other applications for around 5 minutes or more

  5. Switch back to MSFS2024 and put headset back on

  6. Move head to see very low FPS, which should recover after around 1-2 minutes, but may not.

YOUR SETTINGS

What VR peripherals are you using: Pimax Crystal Light

[PC Only] Are you using Developer Mode or have you made any changes to it? no

[PC Only] What GPU (Graphics Card) do you use? RTX4080 Super

[PC Only] What other relevant PC specs can you share? i5 13600kf, 64gb DDR5

2

Hi!

I am also having this issue, or similar.

I am using a Quest 3 with Virtual Desktop, using an Ethernet connection (1000 Mbps).

As an example of my issue. Lets say I do a 4 hour flight. I take off using VR, and performance is perfect (even at a heavy airport like JFK for example). After I’ve reached about FL200+ I’ll usually take the headset off until I’m starting descent. I often use multiple applications during cruise, and performance is stable with no stutters etc (non VR during cruise).

I put the headset on for the descent and arrival, which is great initially (performance wise), right up until after landing when typically performance drops massively, and doesn’t recover. Even if I come out of VR mode, the performance is still terrible. If I restart the sim at the same airport and load back into VR, performance is as it should be without any issues.

I have tried numerous things such as lowering graphics settings, turning off ReBar, etc, to have no effect.