Full VRAM in Open XR with AMD Graphic

[Octave]

Hello,

first of all my specs:

- AMD 9800X3D

- Radeon RX 7900XTX

- 64GB DDR5 6000Mhz

- M2. SSD 1TB 

- ROG STRIX B650E-F Gaming

- VR Headset HP Reverb G2

 

I play DCS in VR, and every time I start DCS through OpenXR, the VRAM of my graphics card gets completely filled – the entire 24 GB of memory. This causes constant stuttering, and the game is almost unplayable. Changing the system settings hasn't made any difference.

I switched from OpenXR to SteamVR, and now everything works as it should: no stuttering and a stable VRAM usage of 14 GB, but with at least 15-20 FPS less.

On maps like Nevada or Caucasus, everything runs fine, but on maps like Marianas or Syria, my FPS drops to 30-35, and I don’t really see the point in lowering my graphic settings further if I could continue to play at full resolution through OpenXR.

Does anybody know what causes the issue of the full VRAM when playing DCS through OpenXR, or which settings might solve the problem that iam able to play DCS through Open XR?

Note: I tested DCS with an RTX 5080 from a friend and didn't encounter any of the mentioned issues with OpenXR.
So, the problem is most likely with my Radeon graphics card.

[speed-of-heat]

what are your graphics settings in game at the moment ?

[Octave]

 

[speed-of-heat]

MSAA x 4 is pretty brutal i don't think i ever went above x2 with my 3090 ,  and maybe shadows to flat... thats the only thing that leaps out; but my german is pretty rubbish.

You should be using OpenXR by default now with your G2. 

You might try some of the settings in Open XR Toolkit  or  you might try using quad views and fix foveated rendering both of those will reduce your vram usage as they will render things in your peripheral vision on lower resolution, which given the G2's small sweet spot you wont be seeing that clearly anyway.

Marianas is a very VERY slow map over land , Syria tends to be better especially once you get away from the airfields... sorry that's all i have 

[The_Nephilim]

2 hours ago, Octave said:

 

Well I know for a fact that Textures on high will cause massive use of VRam. I would set that at medium. but the big thing I see in your screenshot is you have the Max FPS set at 45 that is probally the issue here set it higher..

[Octave]

@Speed-of-heat
There’s not much of a difference between setting MSAA to 4x or 2x. In VR, I need at least 4x MSAA because otherwise the edges flicker too much. With TAA, the image gets too blurry, and to compensate for that, I’d have to increase the G2’s resolution to 150%, which again costs more performance.

@The_Nephilim
I intentionally capped the FPS at 45. Using SteamVR, I get a maximum of 65 FPS in-flight and around 50–55 FPS on the ground. If I don’t set a limit, I get heavy stuttering because my GPU runs at 100% load.

At 45 FPS, it runs very smoothly in SteamVR. Like I said, the problem only happens when I use OpenXR. There, I can reach up to 70 FPS but still have slight stuttering. Also, when pressing RCtrl + Pause, no threads are shown.

 

[speed-of-heat]

are you by any chance trying to run OpenXR via steam? if so don't , run it natively in WMR ...

[The_Nephilim]

26 minutes ago, Octave said:

@Speed-of-heat
There’s not much of a difference between setting MSAA to 4x or 2x. In VR, I need at least 4x MSAA because otherwise the edges flicker too much. With TAA, the image gets too blurry, and to compensate for that, I’d have to increase the G2’s resolution to 150%, which again costs more performance.

@The_Nephilim
I intentionally capped the FPS at 45. Using SteamVR, I get a maximum of 65 FPS in-flight and around 50–55 FPS on the ground. If I don’t set a limit, I get heavy stuttering because my GPU runs at 100% load.

At 45 FPS, it runs very smoothly in SteamVR. Like I said, the problem only happens when I use OpenXR. There, I can reach up to 70 FPS but still have slight stuttering. Also, when pressing RCtrl + Pause, no threads are shown.

 

well I am confused as you say you capped the frames at 45 but get 70 fps I dont see how that is possible? you said you have the G2 VR?

[Mr_sukebe]

As already mentioned, Textures.  Lower them down.

Other things to try:

 - Disable your "home" in Oculus.  That eats a couple of GB of VRAM

 - Use the mod "Empty VR hangar", which also eliminates wasting a bunch of VRAM.

Edited March 7 by Mr_sukebe