F4 in VR Far higher demand on PC

[Kiwispirits]

I have an i7-10700 CPU @ 2.90GHz and an RTX 3080 12gb powering a Crystal Pimax VR headset.I tried the instant action mission for the F4e in the Caucasus map called 'Free Flight'.My headset dropped to 36 fps and is both CPU and GPU bound. Using the F4e special setting of reduced refresh rates did not help.

I copied that same mission into the editor and changed the airframe to my JF-17. This time the mission runs with 45FPS (the target FPS) with 97% CPU headroom and 33% GPU headroom. This is the same performance I generally get with all my airframes and missions.

I realise I could probably fix this situation with a better CPU and GPU. I also know that Heatblur have another optimization technique involving some multithread trickery for the components of their engine which is not switched on yet as they wanted to keep things simple for the initial release and debug, but in it's current form it is not usable for me in VR.

[WolfTangoFox]

I'm running Pico 4 via Virtual Desktop on a 10900K, 4070, and 64 GB of 3200 MHz DDR4.

Yesterday I did a fresh Windows 11 install and was setting up DCS and other things. I fired up the Hornet "free flight" mission, because that's a known "benchmark" to me for testing VR, and I was getting the expected 80-90 FPS. I then fired up the F-4E "takeoff" instant action mission (the one right above free flight), and virtual desktop crashed completely while loading the world. I tried again and got the same result.

Sounds like a very similar issue and a very similar direct comparison to another module. I expected the F-4 to be heavy of course, but running at all would be a good start. 

Edited May 23, 2024 by WolfTangoFox

[Bladigan]

A couple of days ago did some test and all my modules worked at very solid 45 fps (locked using the option in DCS menu) except the Apache (some little drops).

Yesterday with the Phantom and the new patch solid 45fps most of the time but, from time to time, stutters and drops to 30 during 10/20 seconds. In a few tests even 5fps and DCS almost freezed. After that it recovers and solid 45 fps again.

Specs:

Win10, Pico Neo 3, 12700KF, 3070ti, 32GB RAM and M2. SSD.
 

[Kiwispirits]

I did some more testing and found that my FPS drop problem is that the F4e in VR has some sort of bug when the OpenXR Toolkit is used to adjust VR settings. If I disable the OpenXR Toolkit I get the same VR performance in the F4e and the JF-17. This is obviously not a long term solution because the toolkit is needed to get the best performance, but checking interactions in VR between the toolkit and the F4e should give a good starting point for a fix by Heatblur. I was using a Pimax Crystal Headset, Pimax XR runtime and the OpenXR toolkit

I will raise a separate bug report for this.

Edited May 23, 2024 by Kiwispirits
grammar

[Qcumber]

57 minutes ago, Kiwispirits said:

I did some more testing and found that my FPS drop problem is that the F4e in VR has some sort of bug when the OpenXR Toolkit is used to adjust VR settings. If I disable the OpenXR Toolkit I get the same VR performance in the F4e and the JF-17. This is obviously not a long term solution because the toolkit is needed to get the best performance, but checking interactions in VR between the toolkit and the F4e should give a good starting point for a fix by Heatblur. I was using a Pimax Crystal Headset, Pimax XR runtime and the OpenXR toolkit

I will raise a separate bug report for this.

 

Have you tried disabling turbo in OXRTK to see if that is the issue?

Just out of interest, why do you need OXRTK to get the best performance? I only really use it to tweak sharpening and adjust contrast etc. 

[WolfTangoFox]

Disabling the OpenXR Toolkit didn't do a whole lot for me. It did work for a few seconds longer than before, but still crapped itself before everything had a chance to load in properly.

[Qcumber]

2 hours ago, WolfTangoFox said:

Disabling the OpenXR Toolkit didn't do a whole lot for me. It did work for a few seconds longer than before, but still crapped itself before everything had a chance to load in properly.

I would advise submitting this as a bug issue to the VR bugs section. 

[Kiwispirits]

Did some more testing and found the following:
To prevent excessive drop in the FPS for the F4e when using OpenXR toolkit, do not turn on the toolkit feature called Frame Rate Throttling. In my case this cut FPS from 45 to 33FPS and maxed out the CPU.

Other features within OpenXR toolkit such as foveated rendering work without problems.

[Qcumber]

8 hours ago, Kiwispirits said:

Other features within OpenXR toolkit such as foveated rendering work without problems.

Are you not using Quad Views Foveated rendering with a pimax crystal? OXRTK has an old version of fixed Foveated Foveated Rendering only. 

[Kiwispirits]

I will check that out, thanks.