Very low performance headroom in VR when using PP

[karoliens]

Setup:

Ryzen 5 3600
RX 5700 XT
16 GB RAM 3200
Oculus Rift S
144Hz 1440p Monitor

Video Settings:

Oculus Settings:

My goal is to achieve constant 90fps with 23 opponents with PP on since I need to see brake lights.

I used this video as a starting point:

He says that he has constant 90fps with full grid with similar system (1080ti).1080ti is probably a bit quicker than 5700 XT but performance headroom results show that I am constantly in ASW with around -50% headroom when in the pack.
If I leave everything unchanged but turn of PP then it is buttery smooth with headroom fluctuating between -5% to 10%.

How come he has almost constant 90fps and I am stuck in ASW and -50% headroom if the systems are very similar?

 

[karoliens]

GPU/CPU/RAM utilization after 5 laps:

 

[JayMc73]

I have not watched the video but I find the following helped me with VR performance.

You don't have to run the game at the same resolution as your screen. I use 1080p. Also you can run reflections in static mode. There is still enough motion in the reflections on the cars to look good in game. Last thing is you could go to Documents/Assetto Corsa/cfg/oculus and disable mirror texture. That will turn off screen mirroring and save GPU performance.

If you have not tried these I hope they help.

 

[Deleted member 197115]

Good tip on mirroring. Got me excited.
Just checked performance difference running AC benchmark with mirror on and off (1080p) with fpsVR, and the difference is none.
How much improvement did you see with your setup, did you try to measure it with fpsVR, it can save individual runs into graphs with very good stats for analysis.

 

[karoliens]

I did't notice any difference in performance with mirror on or of either.

I think I found a sweet spot to achieve constant 80fps with full grid. I use these settings:

Is it decent for my system? I kinda expected I will be able to SS more.

 

[Deleted member 197115]

Dropping resolution to 1080p should help a bit more.
Also disable AF in game and force in driver for better visuals.
Framerate limit, does it do anything for you?

 

[JayMc73]

Good tip on mirroring. Got me excited.
Just checked performance difference running AC benchmark with mirror on and off (1080p) with fpsVR, and the difference is none.
How much improvement did you see with your setup, did you try to measure it with fpsVR, it can save individual runs into graphs with very good stats for analysis.

Sorry that didn’t help. I haven’t used fpsVR. I just used the in game performance app and checked the CPU usage and frame rate whilst configuring my setup.

Ill try to note every setting I have to post here, but it will be about 24 hours before I get back.

I used to run a full grid with PP on in VR before I started using CSP and SOL and could hold 90fps quite easy as long as the track was optimised and the cars had LODs. Now I limit to about 10-12 cars to maintain 90fps because I prefer real stereoscopic mirrors and all the other cool features that come with those mods.

 

[Blind Potato]

I've been racking my brain with VR and my performance head room is 0-15%, so I'm glad I saw your post. I'm just as confused as you are when I see posts of people getting buttery smooth results with lower hardware.......

Mind you I am running the custom shaders patch and SOL so I know they hammer the system but I didn't think it would cripple the system.

I really don't want to turn off PP because it looks soooooo much better.

I'm running:
Ryzen 5 2600x
RTX 2080 OC
16 GB RAM 3200
Oculus Rift S
120Hz 1440p Monitor

 

[Deleted member 197115]

You can check my guide in this post, might help.

 

[karoliens]

Dropping resolution to 1080p should help a bit more.
Also disable AF in game and force in driver for better visuals.
Framerate limit, does it do anything for you?

Thanks for the suggestion. I'll try that. Regarding AF do you know if it is valid when using AMD GPU as well?
I read that putting frame limit does not require for your GPU to work that much as I can't use more than 80fps in VR anyway. I haven't tested if it has any impact on performance.

 

[Deleted member 197115]

Thanks for the suggestion. I'll try that. Regarding AF do you know if it is valid when using AMD GPU as well?
I read that putting frame limit does not require for your GPU to work that much as I can't use more than 80fps in VR anyway. I haven't tested if it has any impact on performance.

In VR it's hard locked 90hz or whatever HMD refresh rate is.
May be some impact on mirror screen, but then it's better to just use V-Sync.
In older days when AC sync did not work right (stuttering in fast corners), making framerate limit a bit higher of monitor refresh rate (1-2fps) and enabling VSync in driver was a solution.
Wondering if this is where that irrelevant now recommendation comes from.

 

[JayMc73]

I don’t know if this will help anyone. But here are details of my setup.

Before I used SOL and CSP I used to be able to run a full grid at 90FPS average with PP on if the track was optimised well and the all the cars had LODs.

I no longer can as SOL and CSP have features that my system can’t run as easy as plain Assetto Corsa. I don’t mind this though as I enjoy the extra features more than I need 24 cars at 90FPS. I just run a 10-12 car field. Or use ASW for full grids now.

My PC and settings that could run 24 cars at 90FPS average pre SOL and CSP as follows.

Spec.

i7-4770k running at 4.3ghz CPU
Asus Z87-C Motherboard
16gb 1066MHz RAM
1080 Ti GPU in gaming mode using GPU Tweak

In NVIDIA Control Panel I have the following.
Ambient Occlusion-Performance
Anisotropic filtering-Application controlled
Antialiasing FXAA-On
Antialiasing Gamma correction-On
Antialiasing Mode-Application controlled
Antialiasing Setting-Application controlled
Antialiasing Transparency-Multisample
CUDA GPUs-All
DSR Factors-Off
DSR Smoothness-Off
Maximum pre rendered frames-1
Multi Frame Sampled AA(MFAA)-Off
OpenGL rendering GPU-GeForce GTX 1080 Ti
Power Management mode-Prefer maximum performance
Shader Cache-On
Texture filtering Anisotropic sample optimisation-On
Texture filtering Negative LOD bias-Allow
Texture filtering quality-High performance
Texture filtering Trilinear optimisation-On
Threaded optimisation-Auto
Triple buffering-On
Vertical sync-Use the 3D application setting
Virtual Reality pre rendered frames-1

Assetto Corsa video settings in Content Manager.
Resolution-1920x1080,60Hz
Rendering mode-Oculus Rift
MSAA-4x
Anisotropic filtering-16x
World details-Very high
Shadows resolution-2048x2048
Smoke generation-Minimum
Reflection resolution-256x256
Rendering frequency-Static
Rendering distance-1200m
PP filter-Default
Overall quality-Very high
Glare quality-Very high
Depth of field-Off
Motion blur-Off
Saturation-70% my personal preference
Heat shimmering-Off
Sunrays-On
FXAA-On
Mirror resolution-256x1024
High quality-On
Pixels per display-1.5
Skybox reflection-75%
Mip LOD bias-Minus 1
Max frame latency-Auto

I also have screen mirroring switched off in the oculus ini file in the Assetto Corsa documents folder.

Last one is I don’t remember if I set this or it does it on its own. But only Oculus Home is running in the background. Steam VR does not activate for Assetto Corsa. I assume it is a good thing because I don’t know how to prevent it coming on for Rfactor2 and I struggle with FPS in that one.

Hopefully this is helpful for any one in a similar setup.