Valve Index and Steam VR - Huge issue with FPS

[TKNARMZ]

Might be a little long but please read.

My issue is the fact that DCS used to work beautifully in VR.  I know some say if your FPS drops below the selected HZ, example: select 80hz and if it fluctuates from 80-75 or lower, you'll see stuttering.  Im here to tell you that is not how it used to perform!  In fact, I used to use my Valve index and play DCS at 144hz while keeping an FPS anywhere from 35-50 without any frame drops, stuttering or jutters.   Another thing it used to do, if I set it at 144hz, it used to divide the FPS showing 72FPS and now its showing 135, trying to reach that 144fps to match the 144hz.  Which I can't so I have massive stutters.

Again, in the past, I could run DCS fluently at 144hz but let it sit at 35-50 fps.  this was on an older machine too.  now I have to stick with 80hz.

I have reached out to Steam because I honestly believe they messed up Steam VR with their huge update on October 4th 2022.  The version 1.23.7 was the last time it ran correctly.

I can't play most of the maps at all with the same settings I had on a slower machine.  Even the slower machine now acts the same.  If I try to Fly in Nevada near the city it just stutters horribly even on low settings.  Steams response is a cut and paste telling me to send them my Comp information.  Which I have done in the past for over a year now trying to figure this out.  This came to light when I remember exactly when this all started.  It started the day I got my new CPU and Motherboard, which was October 4th.

im so frustrated.  But the good things that have come through all this.  I couldn't get MT DCS to work at all on windows 10, I recently switched to windows 11 and now MT works pretty good.  It would have been nice to see what it could have done on a non broken Steam VR version.  I wish I had more options to run these VR programs but I don't think I can using a Valve index.  I think I will stay away from any VR that only runs on Steam.

Current PC Specs:

AMD 7900x

Nvidia 4090

64GB SGSkill Ram

980 Pro 2 TB SSD

OLD PC Specs:  With the old Steam VR version this PC ran it twice as smooth!  I could play any map fly over any city without one stutter!

AMD 5900x

AMD 6900XT

32GB Gskill ram

980 Pro SSD

 

[btaft]

Hey there, I just had the same experience you did with an almost identical new build.  All the same except I used a 7800x3d instead of a 7900x(3d?).  I was shocked when I first booted up DCS and steam VR.  I had set steam VR to 100%.  What I didn't know at the time was steam VR set at 100% had the resolution per eye to be 6900x6900 which is well in excess of the native resolution of the Vive Pro 2 headset I have (2448 x 2448 per eye).  Looking deeper into why this was the case it looks like steam VR sets the 100% resolution to what they think it should be based on your video card and it has nothing to do with the actual headset native resolution.  When I went back to set this to 140% (3427 x3427) of the native resolution (recommended for working with the distortion of VR), I then got the expected performance.  In my case 2448 x 2448 worked out to be 24% on the steam VR slider and 3427 x 3427 worked out to be 50%.  I am not sure if this is the same problem you are encountering but figured it couldn't hurt to share my experiences.

 

Good luck!

[TKNARMZ]

No, but back in the day I could set my DCS setting to almost MAX settings and no stuttering at all.  Hitting 40-50 FPS which is below 144hz and still no stuttering.  I can't do that anymore.  I now have to use 80hz and keep all my settings to hit 80FPS or I get horrible stutters.  Steam changed something and I don't even think they know its not working correctly. Most VR games don't need this much power like DCS does or other headsets don't use steam so they don't complain about it.  But in my opinion Steam VR is broken and they won't listen to me.

[btaft]

What resolution is your Steam VR slider showing?

[TKNARMZ]

5 hours ago, btaft said:

What resolution is your Steam VR slider showing?

It doesn't matter. But I have both Steam VR set to 100% and DCS set to 100%.  I should still be able to adjust the settings as high as I want to achieve the FPS I want.  If I want 45FPS, like I used too, then I should be able too.  I can't.  Im limited to 80hz and 80FPS.  Anything below 80FPS and I get stutters.  Never used to be that way!  

[btaft]

Actually it does matter, doesn't seem like it should but it does

You are correct in that something is "wrong" with SteamVR.  What is wrong is that its resolution slider is very counterintuitive and completely independent of the native resolution of the headset

I didn't think it would either until I had problems just like you after a new build that was much superior to my old system that worked decent.  Thats when I saw that 100% on the steam VR slider had nothing to do with my headset's native resolution.  Regardless of the headset's native resolution steamVR will set the 100% based on the type of video card you have.

In my case my headset is a Vive Pro 2 with a native resolution of 2448x2448 per eye

Old System (2080 Ti) - SteamVR slider at 100% has a resolution of 2100x2100 per eye (which is actually less than the native resolution of the Vive Pro 2)

New System (4090) - SteamVR slider at 100% has a resolution of 4916x4916 per eye (which is a lot more than the native resolution of the Vive Pro 2)

My solution (what works for me) was to set the SteamVR slider to 50% which equates to 3476x3476 which is pretty close to the 140% recommend rendered resolution to native resolution to account for the barrel effect going from flat to round in a VR headset.

I think if you check to see what resolution steamvr is showing when its slider is at 100% you may be surprised

 

[TKNARMZ]

3 hours ago, btaft said:

Actually it does matter, doesn't seem like it should but it does

You are correct in that something is "wrong" with SteamVR.  What is wrong is that its resolution slider is very counterintuitive and completely independent of the native resolution of the headset

I didn't think it would either until I had problems just like you after a new build that was much superior to my old system that worked decent.  Thats when I saw that 100% on the steam VR slider had nothing to do with my headset's native resolution.  Regardless of the headset's native resolution steamVR will set the 100% based on the type of video card you have.

In my case my headset is a Vive Pro 2 with a native resolution of 2448x2448 per eye

Old System (2080 Ti) - SteamVR slider at 100% has a resolution of 2100x2100 per eye (which is actually less than the native resolution of the Vive Pro 2)

New System (4090) - SteamVR slider at 100% has a resolution of 4916x4916 per eye (which is a lot more than the native resolution of the Vive Pro 2)

My solution (what works for me) was to set the SteamVR slider to 50% which equates to 3476x3476 which is pretty close to the 140% recommend rendered resolution to native resolution to account for the barrel effect going from flat to round in a VR headset.

I think if you check to see what resolution steamvr is showing when its slider is at 100% you may be surprised

 

I know exactly what you are saying and thats not the problem.  The resolution in Steam VR at 100% is sitting at 2016 x 2240.

I pay attention to everything and like I said before, even my old computer is acting like my new one.  They started doing the same thing after the Steam VR update back in October.  I should be able to adjust all setting to hit 40fps.  There is absolutely no reason to get stuttering at 40FPS.  I know what some think, they are going to say you will if you drop the FPS below the HZ the headset is set up as.  But this was never true and it never did that before at all (used to run 144hz at 40 FPS flawlessly).    If I adjust the settings to 50% everything in DCS is extremely blurry!  Unreadable dashboard.  I remember exactly how to use to look and act.  I could read everything in the cockpit, fly over any city, any forest area on any map and not one hiccup.  My settings are no where near what they used to be and I can only fly two maps and if I fly over a city its unbearable.  I appreciate you trying to help.  But the only way to fix this is to get Steam to listen to us.  I try telling them and all I get is a stupid cut and paste response.  

[btaft]

Gotcha,  was hoping it was something simple but subtle like I experienced.  We have very similar systems and I am getting a very fluid experience at 45 fps consistently at higher settings than my old system.  I know in building my system that the graphics card bus would be reduced from x16 to x8 if I put the M2 SSD into the wrong M2 slot.  I know this is a long shot.  Just trying to help.  Something is definitely wrong (stating the obvious)

[TKNARMZ]

2 hours ago, btaft said:

Gotcha,  was hoping it was something simple but subtle like I experienced.  We have very similar systems and I am getting a very fluid experience at 45 fps consistently at higher settings than my old system.  I know in building my system that the graphics card bus would be reduced from x16 to x8 if I put the M2 SSD into the wrong M2 slot.  I know this is a long shot.  Just trying to help.  Something is definitely wrong (stating the obvious)

Maybe its Valve Index.  I get a new headset soon.  Just waiting for the shipment to come in.  I ordered the Bigscreen Vr.  We shall see.  

[btaft]

 

 

On 8/10/2023 at 2:55 PM, TKNARMZ said:

Maybe its Valve Index.  I get a new headset soon.  Just waiting for the shipment to come in.  I ordered the Bigscreen Vr.  We shall see. 

Hi There TKNARMZ,

I saw an advertisement for the Bigscreen VR and it looks intriguing.  I was curious to see what your experience has been?

 

[TKNARMZ]

On 10/17/2023 at 7:19 AM, btaft said:

 

 

Hi There TKNARMZ,

I saw an advertisement for the Bigscreen VR and it looks intriguing.  I was curious to see what your experience has been?

 

Im still waiting on my shipment.  Ordered it right when they announced it but having gotten it yet.  Anytime now.

[btaft]

thanks!   hope you get it soon!  It looks pretty interesting!

 

[TKNARMZ]

received the Big Screen Vr headset.  the visuals are amazing, although it was intermittent.  The headset has issues and they are going to send me a new one. 

[Wyndemere]

Any updates on the Bigscreen?  I have an AMD 7800x3d and 7900xtx, but I'm on the fence about the BB VR for daylight flying.

[TKNARMZ]

On 3/9/2024 at 12:42 AM, Wyndemere said:

Any updates on the Bigscreen?  I have an AMD 7800x3d and 7900xtx, but I'm on the fence about the BB VR for daylight flying.

I had to send it back and get a refund.  Couldn't get it to work.  they even sent me a replacement and it didn't work.  In the end I didn't like how small it is.  It felt like wearing swimming goggles instead of a mask.  When Im swimming, pool or ocean, I prefer a full mask.  I didn't like how it felt. 

[Landei]

But did it solve the initial issue?

[TKNARMZ]

19 hours ago, Landei said:

But did it solve the initial issue?

No.  nothing has.  Like I said, I used to set my VR headset to 144hz. and the graphics a little higher than they are now and that was on an AMD 6900xt.  I now have an Nvidia 4090.  But what ever they did ( either DCS or Steam ) ruined the way it handles VR.  People keep saying if your FPS drops below your HZ, it will stutter.  Well, before it didn't used to do that at all.  The only time I got it to stutter was under 30FPS.  no where near what it needs to be to hold 144hz.  Some maps I can't even play like Syria when flying through the buildings, which used to be super smooth and hitting 40-50FPS.  I truly believe it was a Steam Update not so much DCS itself.  NO HEADSET HAS HELPED.  I have tried three different ones now.  Not even the Varjo. 

[gwizdek]

On 3/15/2024 at 4:48 AM, TKNARMZ said:

Well, before it didn't used to do that at all.

Sorry, you are imagining things or didn't pay attention earlier, or had strange reprojection settings.

• SteamVR: set your Index to 90Hz, 100% global resolution, 100% per app resolution. Disable motion smoothing (reprojection). 
• DCS: disable antialiasing and DLSS. Adjust sharpness slider to yout liking. Verify that you have Pixel Density set to 1.0 on VR tab.
• Check your FPS. You should get 90 frames per second on 4090 easily. Increase SteamVR per app resolution for some supersampling.

You could also:

• add your DCS instalation folder/Saved Games/DCS folder to exceptions in antivirus software.
• check Windows HAGS (on or off) - restart Windows after each change. 
• run with OpenXR API via DCS MT (this should be default by now)

Always try to match your game FPS with your HMD refresh rate (with some headroom).

Using motion reprojection makes the image less sharp than without it. When your HMD is set to 90Hz, for the MR to work fine, you should be rendering at about 60FPS (you need some margin above 45FPS).

Edit:

Don't try to run DCS at 144Hz as it's simply to taxing for the CPU. If you can get DCS to run at 90HZ/FPS, that will be perfectly smooth. Also try 80Hz if needed.

Edited March 17 by gwizdek

[TKNARMZ]

2 hours ago, gwizdek said:

Sorry, you are imagining things or didn't pay attention earlier, or had strange reprojection settings.

• SteamVR: set your Index to 90Hz, 100% global resolution, 100% per app resolution. Disable motion smoothing (reprojection). 
• DCS: disable antialiasing and DLSS. Adjust sharpness slider to yout liking. Verify that you have Pixel Density set to 1.0 on VR tab.
• Check your FPS. You should get 90 frames per second on 4090 easily. Increase SteamVR per app resolution for some supersampling.

You could also:

• add your DCS instalation folder/Saved Games/DCS folder to exceptions in antivirus software.
• check Windows HAGS (on or off) - restart Windows after each change. 
• run with OpenXR API via DCS MT (this should be default by now)

Always try to match your game FPS with your HMD refresh rate (with some headroom).

Using motion reprojection makes the image less sharp than without it. When your HMD is set to 90Hz, for the MR to work fine, you should be rendering at about 60FPS (you need some margin above 45FPS).

Edit:

Don't try to run DCS at 144Hz as it's simply to taxing for the CPU. If you can get DCS to run at 90HZ/FPS, that will be perfectly smooth. Also try 80Hz if needed.

 

I wasn’t imagining anything. I played for years before the update I specified above at 144hz on my valve index.