Developers, please solve the problem with the OpenXR menu

Discussion in 'General Discussion' started by Heiko Woltmann, Oct 17, 2025.

  1. Heiko Woltmann

    Heiko Woltmann New Member

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    I have to start a new thread because I feel like the developers aren't seeing the problem here (https://forum.kw-studios.com/index.php?threads/vr-performance-tweaks-tips.13068/page-52).

    I've been playing Raceroom since 2014, and it's actually my favorite sim racing game.
    Unfortunately, since the update, there have been severe stuttering issues, and there's no longer any way to open the OPEN XR menu and improve performance with foveated rendering.

    I currently have to reduce the shadows so much with my RTX 4090, a 13th-generation i9, and 64GB of RAM that it doesn't look good anymore, or live with severe stuttering, which is absolutely unacceptable, especially in a multiplayer race, and it worked before the update.
    Currently, LMU runs significantly better, at 90fps and very high details without a single stutter.

    Please give us some feedback or a sign that you're working on fixing the problem.

    Thank you!

    PS: Here's a great Nordschleife race where I finished 5th.
     
    Last edited: Oct 17, 2025
  2. FolkSong

    FolkSong Member

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    I think you mean OpenXR.

    OpenVR is the default API used by SteamVR, and it doesn't provide a foveated rendering option.

    I think a more general request to developers should be just to improve VR performance, not necessarily supporting OpenXR, which is probably difficult due to the old engine.
     
  3. Heiko Woltmann

    Heiko Woltmann New Member

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    Yes, that's right. I meant OpenXR, of course, so I changed it. I think it's due to the many OpenVR.DLLs I've tried. ;)
    It worked in Raceroom before the update, and it still works in all other sims like LMU, Assetto Corsa, ACC, ACEVO, DirtRally2, AMS2, and the game with the similarly old graphics engine RFactor2.
     
  4. JDean

    JDean New Member

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    Did you find a solutions for the bad performance. With RTX4080S and Quest 3 its unplayable. micro stuttering everey 4 seconds
     
  5. DaReaLDeviL

    DaReaLDeviL Member

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    Here is a workthrough of our community Members. Please check this and let us know if it worked for you.

    RaceRoom VR Performance Optimization (Pimax + Ryzen 3D V-Cache) – Complete Guide

    After weeks of testing and troubleshooting heavy frametime spikes and micro-stutters in RaceRoom VR with a Pimax headset, I finally found the real bottlenecks and fixed them completely.
    Here is the full summary so others can benefit as well.

    [hr]

    System Setup
    CPU: AMD Ryzen (3D V-Cache – CCD0 cores 0–5)
    GPU: RTX 5090
    OS: Windows 11
    HMD: Pimax (SteamVR)
    Issue: Unstable frametimes, yellow/red fpsVR spikes, micro-stutters

    [hr]

    ✔ The Critical Fixes (Ranked by Importance)

    1. Strict CPU Core Separation – THE GAME CHANGER
    RaceRoom must run exclusively on CCD0 (V-Cache cores). Anything else will cause cache misses and spikes.

    RRRE64.exe:
    • Cores 0–5 only
    • Priority: High
    • Affinity mask: 0x3F
    • Set via Process Lasso ("Always" rule)

    Move these system processes OFF cores 0–5:
    • MsMpEng.exe (Windows Defender) – most important
    • dwm.exe
    • csrss.exe
    • explorer.exe
    • ctfmon.exe
    • RuntimeBroker.exe
    • audiodg.exe
    • chrome.exe (all instances)
    • svchost.exe (heavy ones)

    VR + Steam processes → cores 6–11:
    • pi_server.exe
    • PimaxClient.exe
    • pi_overlay.exe
    • PVRHome.exe
    • steam.exe
    • steamwebhelper.exe

    This eliminates thread migration and stabilizes frametimes completely.

    [hr]

    2. Pimax Client Settings
    • Image Quality: Auto
    • FOV: Normal
    • Dynamic Foveated Rendering: As preferred

    Auto mode prevents CPU/GPU overload and works best with SteamVR Auto.

    [hr]

    3. SteamVR Settings
    • Render Resolution: Automatic
    • Refresh Rate: 90 Hz (fixed)
    • Motion Smoothing: Optional

    Both Pimax + SteamVR on Auto = smoothest results.

    [hr]

    4. Nvidia Shader Cache Cleanup
    Leftover AMD shader fragments caused DX9 issues.

    Steps:
    1. Run AMD Cleanup Utility
    2. Run DDU in Safe Mode
    3. Delete shader caches:
    Code:
    C:\Users\<Name>\AppData\Local\NVIDIA\DXCache\
    C:\Program Files (x86)\Steam\steamapps\shadercache\211500\
    
    4. Reboot
    5. Run RaceRoom 10+ minutes to rebuild shaders

    Steam’s shadercache for RRRE stays empty – this is normal for DX9.

    [hr]

    5. Process Lasso “Kick” After Reboot
    Sometimes affinity rules don’t activate instantly.

    Fix:
    • Open Process Lasso
    • Press “Disable SMT” once
    • Re-apply core assignment for RRRE64.exe

    Optional batch file:
    Code:
    start "RaceRoom" /affinity 3F /high "C:\Path\To\RRRE64.exe"
    
    [hr]

    Optimal CPU Core Assignment (Summary)

    CCD0 – V-Cache (cores 0–5):
    ✔ RRRE64.exe only

    CCD1 – Non-V-Cache (cores 6–11):
    ✔ VR services
    ✔ Steam processes

    Remaining cores (12–15):
    ✔ Windows Defender
    ✔ System services
    ✔ Misc apps

    This setup prevents cache thrashing and stabilizes RaceRoom.

    [hr]

    Key Takeaways
    • Windows Defender on V-Cache cores was the biggest cause of stutters
    • Ryzen 3D CPUs need strict core separation for DX9 games
    • Auto-render modes in Pimax + SteamVR prevent overload
    • Shader cache must be clean after GPU vendor switch
    • Process Lasso sometimes needs a manual refresh

    [hr]

    Final Result

    Before:
    ❌ Yellow/red frametime spikes
    ❌ Micro-stutters
    ❌ Inconsistent VR performance

    After:
    ✔ Rock-solid frametimes
    ✔ All spikes stay green
    ✔ Smooth VR (finally!)
    ✔ Stable and consistent experience

    [hr]

    Tools Used
    • Process Lasso
    • fpsVR
    • AMD Cleanup Utility
    • DDU
    • Windows Task Manager

    [hr]
     
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  6. Vale

    Vale Well-Known Member

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    Interesting. For the same issue with Intel processors that have performance and efficiency cores, which ones should be dedicated to which things via lasso?
     
  7. Makman

    Makman New Member

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    This worked nicely…did mostly the critical settings and the only thing I did differently is custom settings in Steam vr and medium in pimax. Stutter-free gaming!
     
    Last edited: Nov 17, 2025
  8. JAson Murphy

    JAson Murphy New Member

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    I did all of these things and it hasn't fixed my microstutters. I can't figure out what is going on, but KW please fix this issue! The game was running smooth until the past ~week.
     
  9. Daniel Taaani B.

    Daniel Taaani B. New Member

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    With my odyssey plus & upgrade to w11 & a ryzen 5 5600xt couple days ago, I do also have these nasty micro stutter. System (cpu, gpu, ram) all almost in sleep mode like there is nothing to do..

    Funny thing, I have played the last weeks with my old i7 7700k & rtx 3070 on w10 / steamvr with no problems at all.. quality settings as high as possible..

    I have the feeling those stutters have something to do with w11 / newer hardware architectur combined with dx9 and how vr is inplemented..

    With my non x3d iam not rdy to try out your performance guide.
     
  10. Robert Arnott

    Robert Arnott New Member

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    For what it's worth, I have the Ryzen 5 5600x and a GeForce RTX 4080, and had stutters with Windows 10, no change after upgrading to Windows 11. Running Oculus/Opencomposite. So the CPU seems to be the common issue. I've tried all the suggestions on these forums, they've helped get the frame times very low but nothing gets rid of the stutters.
     
  11. Daniel Taaani B.

    Daniel Taaani B. New Member

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    That's interesting. After a few hours of research, I now also have the feeling that it has to do with the more complex CPU architecture and DX9 in connection with VR. I thought TPM was the cause, but AMD should have fixed that with a new chipset driver.

    I'm going to try a few things that have been suggested here... On the other hand, demanding hardware and frame killers like Dirt Rally 2 now run flawlessly in VR on my new system.

    That been said, I might just move on..