[SOLVED] VR performances inconsistency (on same track)

[Pennix_LeGaulois]

Hello Everyone.

 

First I would like to thanks all contributors of this forum. I do not participate much in posts, but I have learn loads of valuable information reading you !

 

I play IL-2 in VR. Like most VR players I have been impressed by the performance boost version 4.006 provided and as a result, I have been fiddling with settings to get better visual quality while keeping close to my headset refresh rate. I am using a personal track to assess settings performances (counting missed frames with Oculus Tray Tool, while keeping the head in the same position).

 

Doing so, I noticed an inconsistency in VR performances that I cannot explain.

Without any changes to the settings, sometimes the performance is lower than usual. It is clearly visible at the start of the track, while the game is still paused :

• with the settings I am happy with, I usually am at a locked 80 fps
• when I have the issue, my fps are fluctuating between something like 65 to 70 fps

The performance difference is also clearly visible on the total missed frames at the end of the track if I play it through.

 

This issue seems to happen randomly after a start or a restart of the game. When occurring, it remains for the whole session (no matter if I reload the track or play another one). I didn’t find a cause or a way to prevent this at launch. Restarting the game is not a guaranteed solution either.

 

Does anyone experience such a thing ?

 

To be clear : I am not saying the problem comes from the game. Although I suspect it is the only game exhibiting this issue, it is the only game I actually benchmark in VR.

I have a feeling there is something (settings ?) not loading properly randomly at game start, but it might not be that at all… However I hope you would have some clue as to what is going on !

 

A few more details, hoping it can help :

Several other things I do/tried/think off :

• I have an OTT game profile for IL2 (SS 1.2, ASW off, CPU priority High, GPU Scaling off). I hear the audio confirmation « game launch detected » every time I start the game.
• In Nvidia control panel, power gestion is set to « maximal performances » on both global parameters and dedicated IL2 profile.
• In Windows power plan, PCI express power management is deactivated.
• it happens regardless of how whether the PC has been idle for a long time, just restarted or being used in a game for long when I launch the game. It doesn't seem to happend when the game run properly, no matter how long I play. -> This makes me think it is not an hardware throttling issue
• I noticed this phenomenom after patch 4.006 (& 4.006b) update, but it might be because it made want to change my graphic settings and go through the benchmark process again...
• I have used steam function to check game's files integrity

 

My rig :

• I5 9600K locked @ 4,59 GHz
• RTX 2060 super (drivers 445.75)
• 32 Go of DDR4 @ 2 666 MHz
• Game is on an NVME SSD
• My headset is an oculus rift S (firmware & Oculus app up to date)
• Windows 10 professional (version 1909)
• Game is a steam version, but I am using open composite.

 

Update on 2020-05-30 :

I can confirm it is not the game's fault.

It appears the origin of the problem is that super-sampling/pixel-density was randomly not starting properly.

• "good performances" situation was in fact the game running with a default pixel density of 1.0
• "bad performances" situation was in fact the game running with the OTT game profile specified pixel density of 1.2

(so "bad performance" situation was actually an "everything running as it should" situation ?)

I should have a look at potential conflicts between Oculus software & OTT regarding pixel-density setup.

Edited May 30, 2020 by Pennix_LeGaulois
found the origin of the discrepancy, update OP accordingly

[dburne]

Have you tried it with ASW set to auto?

Also have a look at your running programs in task manager, see if there are any that are kind of heavy on the CPU and if you can make adjustments there.

[Pennix_LeGaulois]

Just now, dburne said:

Have you tried it with ASW set to auto?

Also have a look at your running programs in task manager, see if there are any that are kind of heavy on the CPU and if you can make adjustments there.

 

Hello Dburne,

 

I have not set ASW to auto, but since it is the exact same track, with the exact same games settings, what makes you think ASW (which should be off) might be responsible for the fps differences ? Especially when the track is still on pause and I am looking at the front forward direction ?

 

I have watch closely the task manager. While I can be entirely sure there is not a sneaky program in there, it doesn't seem like there is. I try to keep my installed programs to a minimum. I also have the habit to perform antivirus updates before my play sessions to avoid any unexpected virus-definition update while in game.

 

To emphasize a bit, the issue is not that I am not at a locked 80 fps, it is that all game settings being equal, I am randomly 10 to 15 fps below these 80 fps on the same recorded track, when I was attaining these 80 fps.

I noticed it while testing settings. In which case the typical scenario would be :

• (1) found settings that looks good, run the track
• (2) fiddle with the setting to see if can have prettier visuals without too much of a fps hit -> restart the game to apply settings -> run the track
• (3) decide to revert back to previous settings -> restart the game to apply settings from point (1)
• and then, apparently at random, sometimes I get the same performances than measured in point (1), and other times I get noticeably worst performances

It is not the only only scenario I experienced, it also happen (again apparently at random) when I start the game to play. If I run my "benchmark track", sometimes I got the lock 80 fps while track is on pause, sometimes I got the fluctuating 65-70 fps while track is on pause...

[dburne]

I would suggest you see how it performs in game with ASW on auto.

If you have it off and have those fluctuations during gameplay you may experience some stuttering.

[firdimigdi]

Enable the app rendertime overlay with OTT and note if the gpu or the cpu frametime goes up when this happens.

[cmorris975]

My experience changes from session to session, but I’m also barely above what I would consider minimum spec for Il-2 VR.

 

Usually my CPU has cores hitting 100% usage when frames are dropping.  It can be a particularly busy mission causing that, or it can also be background tasks doing things.  Multiplayer always runs cleaner.  That’s due to less CPU usage by the game I am sure.

 

Considering my system and the settings I use... the game runs overall pretty decently in VR.  Can’t wait for the eventual CPU upgrade I will inevitably be doing though!

Edited May 30, 2020 by cmorris975

[chiliwili69]

That´s is strange. Typically recorded track should produce very similar results (-+ 2fps on average).

 

It could be due to your 2060 being donwclocked a bit.

 

There is a number of thing you can do independently:

Try to don´t put any SS.

Try to put Clouds to low.

Try to not use OTT.

Try to not use OpenComposite.

Try to disable 2 of your cores in BIOS (first 1-2, secondly 3-4, then 5-6)

[Pennix_LeGaulois]

Hello everyone,

 

Thanks for your feedback !

I continued testing on the same track, now with game updated to 4.006e, and I finally found what's happening !

 

On 5/30/2020 at 8:51 AM, chiliwili69 said:

That´s is strange. Typically recorded track should produce very similar results (-+ 2fps on average).

[...]

It is indeed the behavior I was expecting, and I was startled by the discrepancies.

Running the track two times in a row, I only measured a 20 frames difference over the 185 seconds of track's duration. That's a 0,1 fps difference on average ! 

 

But after a game restart, I could go from a ~785 frames missed to 3415 over the track !

 

On 5/28/2020 at 9:55 PM, Firdimigdi said:

Enable the app rendertime overlay with OTT and note if the gpu or the cpu frametime goes up when this happens.

Thanks Firdimigdi for suggesting to pay more attention to gpu/cpu frametime. I managed to reproduced the problem and noticed App render GPU time was typically increased by ~+20%, App render CPU time by ~+5% & App Queue Ahead time ~+140% !

 

This made me think it was more than a graphic setting glitch from the game.

 

And indeed it was not coming from the game at all : it was the super-sampling (pixel density) that was randomly activated or deactivated at game startup !

• when I was experiencing the "good performances" situation, the game was actually running with a 1.0 pixel density
• when I was experiencing the "bad performances" situation, the game was actually running with a 1.2 pixel density

I guess I would have noticed it if I paid more attention to cockpit's instruments clarity while benchmarking, rather than counting missed frames ^^

 

 

I am now guessing there is a bit of conflict between Oculus software, Oculus Tray Tool general settings and Oculus Tray Tool IL-2 game profiles when it comes to applying super-sampling. I'll have to look into that.

 

Anyhow, now that I am aware of the problem's origin I can resume fine tuning IL-2's graphic settings to my taste !

Edited June 2, 2020 by Pennix_LeGaulois
found a typo...

[firdimigdi]

Glad to hear you are getting to the bottom of this.

Might I suggest that in OTT you disable voice commands or at least disable the ones you don't want to use? I've had it toggle all sorts of shit accidentally during gameplay if my recording device was set to stereo mix - it would pick up the game audio and start triggering voice commands left and right, changing my pixel density, starting steam, all sorts of weirdness.

[Pennix_LeGaulois]

Noted ! 

 

I never used the feature, I think I disabled it... will check if it appears in game profiles though !

[=RS=Funkie]

Can I suggest that you set your OTT SS to 1. But add the supersampling in the OpenComposite.ini file.

[firdimigdi]

2 hours ago, PhunkaeG said:

Can I suggest that you set your OTT SS to 1. But add the supersampling in the OpenComposite.ini file.

 

Note: if you have a profile set in OTT then to use supersampleRatio in opencomposite.ini you need to set the OTT game profile to 0 super sampling or it'll override opencomposite.ini

[dburne]

2 minutes ago, Firdimigdi said:

 

Note: if you have a profile set in OTT then to use supersampleRatio in opencomposite.ini you need to set the OTT game profile to 0 super sampling or it'll override opencomposite.ini

 

Correct.

[=RS=Funkie]

Sorry! Yes, 0, not 1.