Hi all,

 

I got into VR only a few weeks ago.  I've upgraded my GPU to an RX 9070 XT 16GB and then even upgrades the rest of the PC to a Ryzen 9800X3D and 64GB DDR5-6000 (4 DIMMs downclocked to 5600MT/sec).

 

I still am having issues with frame timing with anything more than a small single player mission.  On Flyboy's training or Syria servers, I average 20FPS in VR and I have everything pretty much set to low.

 

Can we compare eachother's performance by specifying what hardware and settings we're using?

 

FWIW, I get pretty good framerates on a 1440p monitor and high settings. 

 

CPU: 9800X3D

RAM: 64GB DDR5-5600

GPU: Radeon RX 9070 XT

VR/Screen: Valve Index

Launcher: Steam/SteamVR

OS: Void Linux 7.2.10

Average VR FPS on Flyboy training server: 20

What headset do you have?

48 minutes ago, Klaiber said:

What headset do you have?

 

2 hours ago, Yatta said:

VR/Screen: Valve Index

My PC specs. 

CPU - AMD Ryzen 5 7600X
MOBO - Gigabyte B650 Aorus Elite AX
Memory - G.Skill DDR5-6000 (4 ea 16Gb. Total 64 Gb) P/N: F5-6000J3238F16G-fx5
Graphics card - PNY GeForce RTX 4080
Storage - 2 each 2TB P3 NVMe PCIe 3.0 M.2 Internal SSD
VR - Pimax Dream Air SE SLAM using OpenXR latest build
OS - Mindows 11 Pro 64 bit

With pretty high graphics settings in DCS 45 - 70 FPS average. 

 

With your hardware you should be getting MUCH better performance.

Here's what Google AI says (maybe ask other AI as well:

AI Overview

Low performance in DCS World multiplayer via VR on Linux is typically driven by a combination of Proton/OpenXR runtime overhead, SteamVR limitations under Linux, and missing environment overrides. Your top-tier hardware (

AMD Ryzen 7 9800X3D

and

Radeon RX 9070 XT

) is more than capable, meaning your bottleneck is strictly software configuration.

Apply the following targeted optimizations to stabilize and boost your multiplayer framerates.

1. Fix the Linux OpenXR / VR Environment Call

DCS heavily favors OpenXR. Running it via standard SteamVR paths on Linux without passing explicit environment flags forces suboptimal Translation Layers.

Open Steam, right-click DCS World, and go to Properties.

Paste the following into the Launch Options to force proper OpenXR device initialization and bypass the heavy SteamVR launcher wrapper: 

ProtonDB

bash

PRESSURE_VESSEL_IMPORT_OPENXR_1_RUNTIMES=1 OXR_RECENTER_STAGE=1 WINEDLLOVERRIDES='wbemprox=n' %command% --no-launcher --force_enable_VR --force_OpenXR

Use code with caution.

2. Verify Your Mesa & Kernel Compatibility

The

Radeon RX 9070 XT

runs on AMD's newer RDNA 4 architecture. On a rolling release like Void Linux, a mismatch in recent drivers can cause severe performance regression or failing pipeline optimizations. 

Level1Techs Forums +1

Ensure your system is updated and verify you are running at least Kernel 6.13.5+ and Mesa 25.0+.

Ensure your linux-firmware package is fully updated to ensure the firmware binaries for the

9070 XT

are correctly mapped. 

YouTube·Level1Linux +2

3. Lower CPU-Bound In-Game Settings (Multiplayer-Specific)

Multiplayer environments stress your

9800X3D

's tracking capabilities due to high unit counts and network parsing. High graphics settings in VR will induce severe 1% frame drops. 

Reddit·r/hoggit +2

LOD Switch Factor: Drop this to 0.4 or 0.5 in the graphics settings. In VR, the slight reduction in distant object models is barely noticeable but saves massive amounts of draw calls in busy multiplayer servers. 

YouTube·Reflected Simulations +1

Preload Radius: Set this roughly between 60,000 and 100,000. Your 64GB of RAM can handle it, but setting it too high forces unnecessary caching over network states. 

Reddit·Tuuvas +2

Shadows & Civ Traffic: Set Shadows to Medium or Flat. Turn Civilian Traffic completely OFF. 

YouTube·Yorick! +3

Upscaling: Since you are on AMD, enable FSR (FidelityFX Super Resolution) or native DLAA (if utilizing Proton's DLSS-to-FSR wrapper translation) rather than running at an un-upscaled 100% resolution scaling. 

ED Forums +1

4. Clear Your Shaders

Corrupted or outdated shaders compiled under older Wine/Proton prefixes often cause heavy micro-stutters and frame drops.

Navigate to your DCS installation directory or your local WINE prefix path (typically under ~/.steam/steam/steamapps/compatdata/223750/pfx/drive_c/users/steamuser/Saved Games/DCS/).

Completely delete the contents of the fxo and metashaders2 folders. They will safely rebuild cleanly on your next startup. 

5. Check System Monado Alternative

SteamVR's native Linux implementation is notoriously unoptimized for complex VR loops compared to its Windows counterpart. If you continue to see poor hardware utilization despite the tweaks above, community consensus for high-end Linux VR points toward running Monado paired with Envision or WiVRn to completely bypass SteamVR’s compositor overhead. 

ED Forums +1

What Proton version are you currently using to force the game (e.g., Proton Experimental, GE-Proton)? If you pull up a frame-time graph, let me know if your stutters point to a CPU frame-time spike or a GPU bottleneck.

 

Thanks Vonrd.  The SteamVR vs OpenXR might be a thing. I think I can get a different OpenXR runtime in use with the standalone version so I'll give thst a try.

 

One thing of note, I notice the framerate drops only once the VRAM is full.  With 16GB I thought if have some decent room to grow but apparently not. When the VRAM is not full, for example on a small single player mission, I get 90FPS with little problem so I think it mostly comes down to VRAM usage I need to get under control. 

Step-by-Step Fixes to Reclaim VRAM on Linux

1. Implement Proton and Environment Variables

Since you are on Void Linux, you can pass specific environment flags to Proton via Steam to force cleaner memory handling and prevent Vulkan from allocating too much "slack" memory.

Right-click DCS World in Steam → Properties → Launch Options, and add:

bash

VKD3D_CONFIG=no_upload_hacks RADV_DEBUG=no_indirect_draw %command%

Use code with caution.

 

• no_upload_hacks: Stops VKD3D from keeping unneeded buffer allocations alive in VRAM.
• RADV Context: Ensures your Radeon Vulkan driver handles VRAM allocation rigidly without letting memory drift into system swap space.

2. Drop "Textures" & "Terrain Textures" to Medium

This is the single most critical change. Setting textures to High in DCS forces 4K skin files into memory for every player's aircraft within your bubble. Dropping Textures to Medium visually alters the cockpit very little in VR, but instantly slashes your baseline VRAM overhead by 4GB to 6GB, keeping you well clear of your 16GB ceiling.

I played around some more after some mixed results Wednesday night's practice.  I found that four settings I thought had little impact infact did have more impact that I thought.

• Clouds: High -> Standard
• Water: Medium -> Low
• Clutter/Grass: 500 -> 0
• Scenery Details Factor: 1 -> 0.75

I still have Medium Textures, Low Terrain Textures, and Medium Visib Range.

Those three changes alone got me from 20fps on the ground in a dark airplane (powered off) in Flyboy's training server to 37fps (85% increase!).  I can't say which ones did the most changes without thoroughly testing each setting change.  Frame times are still wildly all over the place, and that's my next investigation.

I'll do some more tinkering and report some better results here incase someone else needs them.

1 hour ago, Yatta said:

I played around some more after some mixed results Wednesday night's practice.  I found that four settings I thought had little impact infact did have more impact that I thought.

• Clouds: High -> Standard
• Water: Medium -> Low
• Clutter/Grass: 500 -> 0
• Scenery Details Factor: 1 -> 0.75

I still have Medium Textures, Low Terrain Textures, and Medium Visib Range.

Those three changes alone got me from 20fps on the ground in a dark airplane (powered off) in Flyboy's training server to 37fps (85% increase!).  I can't say which ones did the most changes without thoroughly testing each setting change.  Frame times are still wildly all over the place, and that's my next investigation.

I'll do some more tinkering and report some better results here incase someone else needs them.

I can go through my DCS settings with you next time. You should be getting at least 60 fps 

VR Frame Gen might be worth a try. 

 

I have used the Valve Index with Steam VR for many years and agree you should be getting better performance.

It just so happens I just picked up the Big Screen Beyond 2 but have not messed with my settings yet so this will get you started. 

First things first, I run the Caucasus map as the base line then test out the new settings on the other maps.  The other maps tend to not run as well as the Caucasus map.

2nd when trouble shooting only mess with one setting at a time.  If you change more than one thing you will be chasing your tail.

Here are my specs

Mother Board is the Asrock B650E Taichi

AMD 9800X3D 8-Core  4.7 GHZ

Nvidia RTX 4090

64 GB RAM DDR5 5600 don't recall the brand or if I did any changes to the timings. If I did it was the mother board utilities.

I did do a small overclock on my CPU off hand I don't know what it is but  its been stable since I got it. You can push that thing with a CPU fan and it does not overheat.

 

 

On a side note for anyone looking at the Big Screen Beyond 2 the 2E does not work with IL2 Great Battles.  According to forums both versions work with DCS.  The 2E is just their eye tracking version.

 

I lied I did change the frame rate to match my new headset. 

I don't recall what the setting was but don't go chasing the higher ones start with 90 but I have a feeling it was 80.

I player with the SteamVR resolution settings. It defaulted to 150% resolution. I dropped it to 110% some super sampling still for lense distortion) and that made a huge difference. I was able to maintain mostly 80fps last night on Flyboy's Syria TeamOps practice.

25 minutes ago, Yatta said:

I was able to maintain mostly 80fps last night on Flyboy's Syria TeamOps practice.

That's fantastic! I'm about 72, so 80 is perfect.