Getting higher fps (~20%) when IL2 is not the active window?

[69th_EagleEye76]

Can anyone else replicate this? When IL2 is the active window my fps goes down noticeably, but if I alt-tab, like to check steam vr settings or whatever, suddenly I get a big boost in fps in the headset. Sadly the controls won't work unless IL2 is the active window. Does anyone else have this issue or is this some kind of bug. I'm using a Reverb G2, 10850k, with a gtx 1080, 32g ram fyi.

[firdimigdi]

No idea if relevant but I do recall reading about some people mentioning this happen to them with MSFS2020 and DCS, not sure if they were using a G2 though.

[dburne]

Hmm well if the game is not the active window, then there is a lot of processing that is not being computed  that normally would I would think.

[NiiranenVR]

yes - if I understand right  - if the GPU dont have to paint the pixels on the screen , it should give more power painting in the glasses 

[dburne]

11 minutes ago, J5_NiiranenVR-Gfr said:

yes - if I understand right  - if the GPU dont have to paint the pixels on the screen , it should give more power painting in the glasses 

 

No, on screen is just a mirror image of what the GPU is painting in the HMD.

GPU is not having to do extra work to show the mirror image on monitor.

 

[Panzerlang]

3 hours ago, dburne said:

 

No, on screen is just a mirror image of what the GPU is painting in the HMD.

GPU is not having to do extra work to show the mirror image on monitor.

 

 

If that is so, why is it always recommended to run the monitor image at the lowest practical resolution?

[dburne]

50 minutes ago, Hetzer-JG51 said:

 

If that is so, why is it always recommended to run the monitor image at the lowest practical resolution?

 

Just some folks seem to think that helps in performance.

I myself have not been able to see a difference in doing so. But my monitor is only 1080p.

[firdimigdi]

It seems to have originated as a tip from the dev team in the release notes of 2.009 - no idea if things have changed since then regarding the desktop mirror but I doubt it. I do recall having measured it some time a go in frametimes using the oculus debug tool overlay and there was a minor gain so I've kept it at 640x480 ever since.

 

So far the best, less frametime-increasing way I've found to mirror for spectators is with oculus' mirror utility especially since you can pick which eye to display. Set the game to windowed and the mirror util to always on top and it looks great on screen.

[69th_EagleEye76]

7 hours ago, J5_NiiranenVR-Gfr said:

yes - if I understand right  - if the GPU dont have to paint the pixels on the screen , it should give more power painting in the glasses 

That’s the thing. The pixels are still on screen when Steam vr window is active. The Steam vr box is off to the side and il2 is still being displayed though not the “top” or active window.

[dburne]

These discussions have been going on ever since IL-2 got official VR support in early 2017.

Every VR game I am aware of out there produces a mirror copy on the monitor. Even games made for strictly VR.

Usually just one eye copy though, IL-2 is the only one I am aware of that shows both.

DCS gives the option of which eye to mirror.

 

[Dutch2]

You can all test this on a very simple way: run the benchmark test and do one run with monitor on and one with a shutdown of  your monitor.  https://forum.il2sturmovik.com/topic/66924-syn_vander-benchmark-v6-to-measure-il-2-performance-in-monitor-vr/

Or very simple, when running a GPU intense mission (full of high quality clouds), on/off switching your monitor and keep a close watch on your ingame FPS digit. 

Edited February 2, 2021 by Dutch2

[NiiranenVR]

Yes ..... Hmmmm ..... Why have a screen - i have my glasses on ?

 

I never tried , but maybe it's possible to start pc and manage everything with the glasses on 

Could be a help if one day , have a little cockpit instead of office chair and table 

[dburne]

[SCG_Fenris_Wolf]

On 2/1/2021 at 6:07 PM, Hetzer-JG51 said:

 

If that is so, why is it always recommended to run the monitor image at the lowest practical resolution?

Because it does affect people running resolutions beyond 1080p while adding anti-aliasing as an exponential multiplier to it. Many do that.

 

So common consensus, as a baseline, is to recommend to lower desktop resolution. Then people do that, and the odd 50% who'd keep running at 1440p or 4K without that recommendation won't suffer from nerfed performance.

 

People like you are rare and beyond that, who are interested and actually ask the right questions. So you're safe to select what you deem appropriate. But the average user isn't, he wants presets and doesn't understand nor care much what's beneath the surface. Call it the smallest common denominator.

Edited February 3, 2021 by SCG_Fenris_Wolf

[69th_EagleEye76]

Still no idea what causes my initial problem. Guess I'll submit a bug report.

[firdimigdi]

Check here what a user named Ronson1909 says specifically in his second post - however he is on PSVR while the OP is on a G2:

https://forums.flightsimulator.com/t/losing-focus-of-the-sim-i-get-an-increase-of-nearly-10fps/344779

Edited February 4, 2021 by Firdimigdi

[[APAF]VR_Spartan85]

On 2/1/2021 at 5:13 AM, 69th_EagleEye76 said:

Can anyone else replicate this? When IL2 is the active window my fps goes down noticeably, but if I alt-tab, like to check steam vr settings or whatever, suddenly I get a big boost in fps in the headset. Sadly the controls won't work unless IL2 is the active window. Does anyone else have this issue or is this some kind of bug. I'm using a Reverb G2, 10850k, with a gtx 1080, 32g ram fyi.

try checking the Graphics option in windows for

same thing here with dcs and il2....i turned it off and much better

Hope it helps

 

 

Edited February 15, 2021 by [APAF]VR_Spartan85

[firdimigdi]

@69th_EagleEye76 did you by any chance resolve this? Have a pal who's encountering much the same. Framerate tanks when the game is focused and once he alt-tabs out it jumps back up to 90fps - happens even with replays.

[firdimigdi]

Figured this out - posting here in case someone else runs in to this:

 

Under the WMR For Steam options (only accessible in VR afaik through the Steam dashboard) there is an option under Graphics called "Force DirectX 11" which needs to be enabled. Once so then the game is smooth either focused or unfocused.

 

So, going by descriptions about what this setting does, I guess it's some sort of reprojection issue? Odd as reprojection was disabled for IL2.

Edited May 13, 2021 by 335th_GRFirdimigdi

[jollyjack]

I always thought that DirectX11 is chosen if you choose Windows7 compatibility in Windows 10?

[firdimigdi]

Well IL-2 (and DCS which also exhibits the same behavior) are DirectX11 titles.

That option is written as "forceDisableDX12" : true in steamvr.settings so maybe it's doing some weird calls to DX12 for parts of its operations when it's set to "false" - reading up online some people seem to suggest that enabling it has something to do with using the GPU or the CPU for reprojection calculations but I can't find any documentation to verify this.

[FTC_horsky]

For me even with my previous headset RiftS and now with the G2 when I feel performance starts to dip a bit I alt tab to desktop and then back to the game and performance is fine again. Always thought it was strange, will try to force dx11, thanks for the tip 335th_GRFirdimigdi.

Edited May 13, 2021 by SvAF/F16_horsky

[firdimigdi]

Never noticed anything on my rig with the Rift S but then again I don't run steamvr for that or have to go through WMR. This stood out immediately with the G2 both in IL2 and DCS when we were tweaking the settings on a 2080 to get it to play smoothly, as soon as the game was focused it'd drop fps considerably and the steamvr graph would show dropped frames - alt-tab out and it'd go steady 90Hz with sub 11ms frametimes, no synthetics, no spikes. Quite frustrating. I'll have to see if this is the case whenever I get my G2.

[FTC_horsky]

I forced dx11 but results were same same, I didnt notice any difference but as soon as I alt tabbed out and in again all was good, tried only in qm though, will give it a go in mp as well.

 

This is really random, what I have experienced in mp is that often when you spawn in on an airfield, performance tanks, all understandable, load in of objects and so on, so then I tried to immediately alt tab out and in again just to see if it was the object loading, no, performance went up directly.

 

Another observation in mp is randomly as well on a server with heavy clouds a lot of planes, stutter comes, alt tab out and in, stutter disappears.
 

[firdimigdi]

This which you describe sounds like an entirely different issue. Perhaps monitoring GPU/CPU usage when it happens could yield more clues.

Only time I've noticed something like what you describe was years ago when I would use a blue-filter overlay (like flux or windows 10's "night light") or in situations where some sort of overlay would kick-in (nvidia overlay, steam, MSI afterburner etc) or lurk in the background.

[Ala13_UnopaUno_VR]

The same thing happens to me in DCS that loss of 20 FPS when I have the headset removed (it continues to give signal and render) and when I put it on (focused) it lowers those fps and that fluidity, if I want it to go smooth, it does not let me control the booth, since I'm '' on the desk '' and if I want to touch the booth, it will stick to me and drag the image, I DON'T KNOW HOW TO SOLVE IT, il2 is fine for me

[dburne]

2 hours ago, Ala13_UnopaUno_VR said:

The same thing happens to me in DCS that loss of 20 FPS when I have the headset removed (it continues to give signal and render) and when I put it on (focused) it lowers those fps and that fluidity, if I want it to go smooth, it does not let me control the booth, since I'm '' on the desk '' and if I want to touch the booth, it will stick to me and drag the image, I DON'T KNOW HOW TO SOLVE IT, il2 is fine for me

 

What do you mean by " the booth "?

[Ala13_UnopaUno_VR]

24 minutes ago, dburne said:

 

What do you mean by " the booth "?

Descktop

[dburne]

1 minute ago, Ala13_UnopaUno_VR said:

Descktop

 

Ok so are you saying the image in the headset is moving with your head, rather than you looking around the image?

If so that would sound like a tracking issue.

What headset?

Running any mods in DCS?

[Dutch2]

Sorry but I can not find  any force to DX11 option in the Steam files, its only the force to DX12 option, changing this from 12 to 11 I do not know if thats any help for improving FPS. 

[firdimigdi]

16 minutes ago, Dutch2 said:

Sorry but I can not find  any force to DX11 option in the Steam files, its only the force to DX12 option, changing this from 12 to 11 I do not know if thats any help for improving FPS. 

 

In steamvr.vrsettings it is this section which corresponds to the settings for the WMR plugin:

 

   "driver_Holographic" : {
      "correctHiddenAreaMesh" : true,
      "enableSkeletalInput" : false,
      "forceDisableDX12" : true,
      "hapticsDisabled" : true
   },

 

The "forceDisableDX12" is basically the "Force DX11 mode" you find in the menus of the WMR For Steam plugin if you open up the steam dashboard and click on the WMR icon. If "forceDisableDX12" is not present or false then it means it will try to use DX12, if set to true it will use DX11. This only affects the problem mentioned by the OP which I also found to be happening with my friend's G2 setup - it is verified and it reproduces 100% of the time, this is not a thing to change to "improve FPS" per se but if you find that you alt-tab out of the game window and steam shows you a perfectly solid green chart of frames and then when you alt-tab back in it has gaps showing dropped frames then this is very likely the cause.

 

Edited May 14, 2021 by 335th_GRFirdimigdi
clarity