investigating Large performance drop in VR after updating to 2.8

[Jenson]

As I flew a few missions during the weekend in VR, my feeling is that not only performance dropped in 2.8, but the image quality also gets worse than 2.7. 

When I look around (in VR), the contrast/brightness will adjust automatically but not in a natural way, which gives a poor experience. In the last 2.7 version, the scene looks much more natural than 2.8 (in VR, maybe it looks better in 2D with 2.8). I assume it's an issue from contrast/shadow but not sure. 

I hope ED could take this issue more seriously and fix both quality and performance issues in 2.8, otherwise the upgrade looks like a step backward for me (not intend to be negative but just wanna give this feedback to the developement team) 

Thank you ED as always!   

Edited November 14, 2022 by Jenson

[YoYo]

16 hours ago, Burt said:

The only way is to go back to 2D. I cant tweak this perf issue out. 

No, never. We have other sim with VR luckily  too.

[SharpeXB]

On 11/11/2022 at 10:49 AM, Jarmak said:

As someone who actually does project management as a job IRL you don't have a public test build, you have a primary public release that you are releasing as WIP, and a backup stable build that your community barely touches.

There are a wide variety of methods used by software firms to keep their open betas and test builds from becoming the primary version their customer's are using, in order to avoid this very issue. ED does pretty much exactly the opposite of that and spends all of it's marketing promoting the open beta releases while barely mentioning the stable version. As an extremely predictable result the primary product your customer base is consuming is the open beta, and that customer base is going to have some expectations of a base level of functionality.

And honestly, it really doesn't matter what you think about it, what you label things, or how much you argue about it. Your customers have developed expectations as the very predictable result of decisions you've made in how you position the product, and they're going to be upset if you don't meet them. Telling them they're not allowed to be upset is just going to make them more upset; this is marketing 101 stuff. 

Positioning it as a WIP/Open Beta buys you a lot of leeway to have glitches or temporary downtime in functionality, but tapping the open beta sign at your power users when they're upset it's just straight not working for them anymore is not going to get you anywhere productive. 

The problem with what you’re suggesting is that it doesn’t recognize the reality that DCS is a very complex game with a tiny player base. So a closed Beta test wouldn’t generate enough feedback and then the bug tracking and fixing would simply take too long. Nobody is forced to use the Open Beta, it’s the player’s choice. Personally I have never used it. The implication that ED doesn’t test this themselves is a bit silly as well. 

Edited November 15, 2022 by SharpeXB

[fab.13]

Hello,

Maybe the performances problem in OB 2.8 is related to FullScreen subject ( ALT ENTER not working anymore since few patch )

I applied a workaround in the thread bellow about ALT+ENTER and performances are very better for now ( 90 hz everywhere in my test mission as a rift user )

For the few tests i made, i keep the workaround.

Could some VR users ( other tahn rift  ) test the performances with this workaround ?

See this thread :
 

 

[speed-of-heat]

1 hour ago, fab.13 said:

Hello,

Maybe the performances problem in OB 2.8 is related to FullScreen subject ( ALT ENTER not working anymore since few patch )

I applied a workaround in the thread bellow about ALT+ENTER and performances are very better for now ( 90 hz everywhere in my test mission as a rift user )

For the few tests i made, i keep the workaround.

Could some VR users ( other tahn rift  ) test the performances with this workaround ?

See this thread :
 

 

yes tested with a G2 and WMR/OpenXR no difference in performance with this change.

[fagulha]

Heads up in case you´d miss it: 

 

[ags]

No measurable differences, as indicated by OpenXR toolkit or right control pause via alt-enter does on a 4090, 13900k, 64GB DDR5.

And Crysis runs fine!

[fab.13]

Let’s see what happen about oculus users ( my test ) or headset without WMR…

[slughead]

I have tried this. I concur that ALT+ENTER is broken and this fixed it. I believe I noticed a small improvement in frame times but nothing huge. What I did notice is that with this change and ALT+ENTER it introduced lots, I mean LOTS, of shimmer. It's as though DCS is producing a lower res image. If it is, this would explain the improvement in frame time. For me though, the loss in image clarity/quality far outweighs any gain in frame times. Have you noticed the shimmer?

[fab.13]

22 minutes ago, slughead said:

I have tried this. I concur that ALT+ENTER is broken and this fixed it. I believe I noticed a small improvement in frame times but nothing huge. What I did notice is that with this change and ALT+ENTER it introduced lots, I mean LOTS, of shimmer. It's as though DCS is producing a lower res image. If it is, this would explain the improvement in frame time. For me though, the loss in image clarity/quality far outweighs any gain in frame times. Have you noticed the shimmer?

I suppose you are an occulus users ?

I have not noticed lower quality yet ( 1.3 pixel density)

the next missions i’ll fly will be done with fullscreen mode ( as for many years) and in 90 htz  I will Check about that

 

[slughead]

No. Reverb G2, on OpenXR PD 1.0, 4090.

[RuskyV]

For the rift s using the OTT I set a profile for DCS and set the desktop resolution to 800x600 (only accessible as an option throught creating a profile) and then set ASW to 30hz.

This gives a cap of 27FPS in game but the frame times are alot lower giving an extremely smooth experience.

I'm not sure chasing higher FPS in certain circumstances is the solution. There may be more here to do with the headsets and not just FPS.

 

[fab.13]

6 hours ago, RuskyV said:

For the rift s using the OTT I set a profile for DCS and set the desktop resolution to 800x600 (only accessible as an option throught creating a profile) and then set ASW to 30hz.

This gives a cap of 27FPS in game but the frame times are alot lower giving an extremely smooth experience.

I'm not sure chasing higher FPS in certain circumstances is the solution. There may be more here to do with the headsets and not just FPS.

 

Yes !

I read another hread about that and not tested yet ( perhaps you are the creator of the thread  )

My first goal was to retrieve the 90hz experience i had before open beta 2.8 ( computing capabilities  )
ALT-ENTER is an optimisation that we can benefit in front of new graphic functionnality added by DCS ( ask more computing )
We are using ALT-ENTER for many year to get the better of our rig,  whatever the settings ( not seen shimering yet ).

Then after we could change some settings
Reduce Frequency may help to get better quality and smooth, true.
I was used to set ASW to 30 or 45 when my GPU was not so powerful than now ( 1060  -> 1080ti )
I'll give a try with ASW 45 or ASW 30 in order to compare to my 90hz experience in the same mission

Limiting FPS are done by some G2 users i know ( 60hz i believe ) in order to keep smooth and reduce some bad VR effects ( ghosting .. )

[Eldur]

On 11/4/2022 at 5:12 PM, YoYo said:

I think not only in VR, but in VR ii is more visible than on 2D screen (VR is very sensitive to any FPS downgrade).

 

Definately something going off in general. In 2.8, I do have less fps in pancake than I had in 2.7 in VR. And I've been rolling back to double check thrice. The weird thing though is that sometimes (in 2.8 that is, not affecting 2.7), the fps start out in a similar ballpark to 2.7, but then drop a lot after the airplane selection dialogue. Like crashing down from 55-70 to 20ish (in VR) or from 120+ to 30ish (in pancake). Feels like the GPU is entering sleep mode for some weird reason without any chance to get it back up until after a DCS restart and then it's only good until the a/c's been selected. Again, not happening with 2.7. Tried that "prefer max performance" setting in the nvcp already, no luck. And I prefer not to have that on anyways, I can't afford the thing being ramped at 250+ Watts all the time. Electricity prices are far beyond the moon these days. Still trying to nail it down on my side though (altering settings, driver updates etc), just dropping my first observations before dumping an in depth report.

[Sr.]

3 hours ago, fab.13 said:

Yes !

I read another hread about that and not tested yet ( perhaps you are the creator of the thread  )

My first goal was to retrieve the 90hz experience i had before open beta 2.8 ( computing capabilities  )
ALT-ENTER is an optimisation that we can benefit in front of new graphic functionnality added by DCS ( ask more computing )
We are using ALT-ENTER for many year to get the better of our rig,  whatever the settings ( not seen shimering yet ).

Then after we could change some settings
Reduce Frequency may help to get better quality and smooth, true.
I was used to set ASW to 30 or 45 when my GPU was not so powerful than now ( 1060  -> 1080ti )
I'll give a try with ASW 45 or ASW 30 in order to compare to my 90hz experience in the same mission

Limiting FPS are done by some G2 users i know ( 60hz i believe ) in order to keep smooth and reduce some bad VR effects ( ghosting .. )

I had used my G2 in 60Hz mode sine OpenXr came out, and was always thrilled at the clarity and sheer performance with high settings, even running 2x MSAA I could maintain enough of the 60fps and low GPU frame time to never see a stutter (motion repro OFF).

Since 2.8, it was a stutter fest.  

[slughead]

Are people monitoring their CPU temperatures and power draw? If you are overclocking your CPU, you may well be getting into states where it is being thermal and/or power limit throttled.

[darkman222]

1 hour ago, slughead said:

Are people monitoring their CPU temperatures and power draw? If you are overclocking your CPU, you may well be getting into states where it is being thermal and/or power limit throttled.

And if so, that would also have been the case before the update. So what?!

[slughead]

5 minutes ago, darkman222 said:

And if so, that would also have been the case before the update. So what?!

Not necessarily. New features in the update are clearly working our machines harder. Some may be on the edge of performance and the update may have pushed them over. It’s not going to do any harm to check.

[speed-of-heat]

temps are unchanged, indeed the amount of temp headroom i have is stupid. bear in mind DCS taxes the CPU not at all in terms of the raw performance available, 

 

 

[HeavyGun1450]

Looks like ED has once again neglected to fix Flat Terrain shadows this update.

 

[darkman222]

In the meantime I am just satisfied with whatever DCS looks on the lowest presets as long as we get the lost performance back. Will do some testing later if there was something done that actually affects performance in a positive way...

[Art-J]

Guys, experiment with settings posted by fab.13 here:

For me, the right combination seems to have brought overall performance back to 2.7 levels in 2D (haven't measured fps, but the dreaded 2.8 frametime stuttering is gone for good). I know results might be different for VR users, but it's worth trying.

[some1]

Going full screen never gave me noticeable gains in DCS in VR, besides, both shots in my original post were made in windowed mode. 3 weeks and 2 patches later, flat shadows are still broken, and with them enabled, the performance is just as bad as I showed in the first post. 

[speed-of-heat]

no appreciable difference in performance between the two versions 2.8 versions

[darkman222]

35 minutes ago, some1 said:

Going full screen never gave me noticeable gains in DCS in VR, besides, both shots in my original post were made in windowed mode. 3 weeks and 2 patches later, flat shadows are still broken, and with them enabled, the performance is just as bad as I showed in the first post. 

What flat shadows do you mean? "Terrain shadows" or "shadows" in the left column? With both of them off I still have had a loss of 2ms GPU frame time. I dont care if the look is broken. I care if disabling it just does nothing performance wise.

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