Guides:AMD X3D Series Processors

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Optimizing Your AMD Ryzen X3D Processor for VRChat

The AMD Ryzen X3D processors, IN particular the Dual CCD items like the Ryzen 9 7950X3D , leverage 3D V-Cache technology to boost gaming performance, making them excellent for VRChat, as single core performance and resolving of materials and shaders per cycle is needed to keep frametimes low.

This guide will help you maximize your X3D processor’s potential for VRChat, based on tuning tips and AMD's own documentation, especially if you've UPGRADED your CPU to a dual CCD Unit without re-installing windows.

In addition, the UEFI Bios "optimized defaults" are often not optimal for core-parking and boost, especially if your system is self-built, but this is a separate tutorial.

Note: With anything involving advanced system configuration, only make changes if you're comfortable with troubleshooting. These changes may or may not make other games run worse, but in most published expert experiences, including AMD's own documentation, these changes are good for VR Games (especially running on Unity or SteamVR native) in general.

Understanding the Ryzen X3D

The Ryzen 9 7950X3D (and it's newer models, the 9900X3D and 9950X3D) features 16 cores and a massive 128 MB to 144 MB of L3 cache, thanks to its 3D V-Cache design. On the 7950X3d, one of its two CCDs (CPU Complex Dies) has an additional 64 MB of stacked cache, totaling 96 MB of L3 for that CCD, while the other has 32 MB. This setup excels in games like VRChat, where large caches reduce latency for frequent data access—think avatar loading, physics calculations, and world rendering. However, the Single CCD chips such as the 9800X3D and 7800X3D Generally do not suffer from something known as "Cache-Miss". This can be avoided with a system configuration which insures that VRChat is effectively "Landing" on the correct CCD.

VRChat benefits from single-threaded performance and cache efficiency more than raw core count, aligning well with the X3D’s strengths.

Note: This will not be an exhaustive guide, and is focused solely on the situation with Microsoft Windows 11.

Step 1: Update Your System, (Windows 11)

To get the most out of your X3D processor, the short steps are as follows:

  • BIOS Update: Ensure your AM5 motherboard has the latest BIOS. This improves compatibility and optimizes scheduling for the X3D’s dual-CCD design.
  • AMD Chipset Drivers: Download the latest chipset drivers from AMD’s website. These include optimizations for directing VRChat’s workload to the V-Cache CCD.
  • Windows Game Mode: Enable Game Mode in Windows Settings to prioritize gaming performance. In some previous tutorials, turning game mode OFF was beneficial for VRChat and VR Games due to the way that VR renders many sub-processes. This is not the case with these particular processors, if you want optimal performance.
  • XBox Game Bar: AMD's stack requires the Xbox Game bar. You can Install Xbox Game Bar via Microsoft Store (no login required) https://apps.microsoft.com/detail/9NZKPSTSNW4P?hl=en-us&gl=CA&ocid=pdpshare
  • Use the Balanced Power Profile Mode

https://community.amd.com/t5/gaming/how-to-set-up-your-system-with-a-new-amd-ryzen-9-7950x3d-or/ba-p/589464

Step 2: Optimizations to park cores.

  • In Device Manager, there should be a System Device called "AMD 3d V-Cache Performance Optimizer" Look for it, if it's missing, re-install the chipset drivers.
  • Open Services (CTRL+Shift+Esc) and look for amd3dvcacheSvc AMD 3D V-Cache Performance Optimizer Service Running
  • Fix steam SteamVR undoing optimizations. By default, SteamVR's Lighthouse startup sequence SWITCHES Windows into the "High Performance" power mode. This undoes all the careful optimization that Microsoft and AMD have done to make sure the processor boosts to the limit, and chooses the right core.
    • You should DELETE the other power modes to prevent this, and only use "Balanced". This is counter-intuitive based on the title of the power mode, but in short, "High Performance" mode locks your processor to it's highest non-boost frequency as a "Floor". This generally makes it get very hot, and will prevent single core boosting. In the "Old Days" processor core speed switching caused stuttering and latency: This is likely why Valve's engineers decided to enforce this in the Lighthouse drivers. AMD's modern x3D processors do not have this problem when combined with Windows 11's newest kernel.
    • Note1: This process can be easily reversed and is safe to do. Windows will occasionally re-instate these power profiles, after major windows updates. Check for them.
    • Note2: As of writing, Lhun is unaware of a way to use SteamVR's Lighthouse driver to prevent the power mode switch. The driver is looking for the word "High" or "Performance" as well. You CAN make a custom power profile which is a copy of the Balanced profile and simply call it High Performance, but Lhun has not tested this at length. Lhun does not know if the optimizations from AMD will make it into that copied profile in the same way that just using the built-in one would.
      • To delete the other profiles: Launch CMD as Administrator. Switch to the "Balanced" profile first. Run the following commands.
        • powercfg /list
        • Get the list of power configuration GUID's from windows. Make note of the GUID's from every other profile except Balanced
        • powercfg /delete <GUID> (replace <GUID> with the actual GUIDs for High Performance and Power Saving you found in the previous steps)
        • For example: powercfg /delete 85f4908e-4380-47d6-8a79-f4a099526dfa
        • Reboot windows. Make sure that there is only one power Profile present, called "Balanced". You can safely adjust sleep timing and other settings, but do not touch "processor minimum" or any setting marked by AMD. It's best to leave everything alone
      • Finally, if you would like, you can guarantee that the ProcessIdleTasks and KGL Version is updated by running a special command: This may take a very long time, DO NOT touch your keyboard or mouse during this process, and this is only recommended if you've upgraded your processor without installing windows. Tip: run it, hide your keyboard and mouse from your cat, and go to bed.
        • In an admin command prompt run: cmd.exe /c start /wait Rundell32.exe advapi32.dll,ProcessIdleTasks
        • Wait. Once complete, reboot.
Rationale, and why you must use Windows 11 (for now):

https://learn.microsoft.com/en-us/windows-hardware/customize/power-settings/configure-processor-power-management-options

Provisioning is a deep topic. Microsoft's learn site linked above has details about what this is, how PPM works, and the X3D Chips have a <Condition Name> entry in them now. This pattern is AMD Ryzen 9 . *X3D.*

What is Windows Game Mode?

Troubleshooting

  • Stuttering: Ensure Windows schedules VRChat to the V-Cache CCD. Make sure Xbox Game Bar knows it's a game. (https://support.xbox.com/en-US/help/games-apps/game-setup-and-play/how-to-make-xbox-game-bar-remember-or-forget-a-game)
  • Overheating: If temps exceed 85°C, reduce PBO in UEFI or improve airflow in your case.
  • Low FPS: Check GPU usage—VRChat is also GPU-bound. Pair your X3D with a strong GPU like an RTX 3080 or better, and make sure to set the driver to "Prefer Maximum Performance". Sometimes, the GPU will go into a lower power state when MSAA is set to off. Consider using 4x to saturate the bus.

Conclusion

The Ryzen 9 3D V-Cache and high clocks make it a powerhouse for VRChat. By making sure windows is running the correct drivers, you'll have a good experience and high framerates.

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