Where is the bottleneck? VR jumping to 45 FPS

So, I decided to fin out why sometimes my VR jumps down to 45 FPS. I thought it was because I was simply running too high settings. My GPU memory was indeed maxing out, so I decided to lower some GPU memory intensive settings.

Now nothing is maxing out at 100% anymore. My GPU is running 90 FPS at 70-80% GPU usage, highest CPU core usage is around 50-80%.

Spoiler: MSI afterburned 90 FPS

Yet at some points it jumps down to 45 FPS, only using 40-50% of the GPU. Now I thought it would be bottlenecking somewhere else, but that also doesn't seem the case.

Spoiler: MSI afterburner 45 FPS

This was all done with 23 AI, and I let my car being taken over by AI.
I've got 8 gigs of vRam, and 16 gigs of normal RAM.

Now the fun question is, where could the bottleneck be from?

 

I use fpsVR
This shows the performance of the CPU and GPU in real time, highlighting the peaks.
There are different types of graphs.
More detailed to config everything and less (but enough) to use normally.

 

Sounds like you have ASW on (or some similar technology if you are not using Oculus). If it can't maintain 90 FPS, then it will automatically drop down to half of that FPS, i.e. 45. The solution is to either turn off ASW or make sure you have GPU headroom to always run above 90 FPS.

 

The index half the FPS automatically.
As far as i know you can't disable this.
I don't know what HDMI has Remco

 

That is the thing. I know that the headset does that automaticly. But the GPU isn't coming above 90% and has no reason to then go down to 45 FPS right? Or does my usage have to be below 80%?

 

Your fps depend too on the CPU.
And you have to check the peaks (when, where and how much occur)
For this us very usefull the fpsVR (i don't get any commision )

Every yellow line meand that the GPU is'nt capable to render the fps
But if you have the yellow lines in the CPU the result will be the same. You'll have a low load of GPU but your CPU will be the bottleneck.
You have the info by cores too.
And more usefull info

 

What I am about to say is partially offtopic (partially).

I strongly advise against the use of reprojection or ASW Oculus.

It’s 10 billion times better in native resolution :

Much smoother, no micro jerks, no artifacts, and uselessness of the "stabilize horizon" functionality which is not realistic and causes loss in immersion.

What you need to do is set rF2 so that you get your 80/90 FPS 99.5% of the time on the circuit and the most demanding cars (Nurburgring GP).

The race conditions (clouds, rain, 24h cycle, AI number, multiclass, etcetera) must condition the chosen graphic settings.

On Oculus you can deactivate the ASW auto (I deactivate it systematically).

For other VR headsets, this is probably possible ?

 

With the ASW oculus activated, the processor is much, much more stressed.

The number of AIs may then be too high.

 

With Index, no

 

That's why I also looked up if my CPU was a bottleneck, but the highest thread usage is 60%, nowhere close to the limit, as you can see on my provided screenshots

 

But you can have 60% of usage and have a little peak to 100% that provokes stuttering.
You're not going to realize about it.
The fpsVR shows every peak and you could know where is the problem.

 

Where I can see the CPU peaks? Plus explain. I have FPSVR
You have a very hot GPU.. 84C

 

1. Every vertical line is a peak
2. If the peak arrives to this line this will provoke stuttering and the fps will go down

 

That's fine with (most of) todays GPUs, anything over 90c and you should perhaps worry, over 95c and you might wanna seriously think about a fire extinguisher purchase!

 

I didn't see this
It's not my pc. I'm not at home.
Just an image taken fron the Internet

 

Just out of my own curiosity, what kind of a difference do you see from turning the mirrors off?

 

Thanks guys..

 

Oh sweet stats app! Does it work for us mortals without VR just to track CPU/GPU performance?

 

I don't think so, because this is specific to work with SteamVR.

 

That was the question I was going to ask.

With my Rift S I use opencomposite (openVR) that is to say that I do not use SteamVR :

So no need to buy this software (FPSVR) ?