Bad performance with Vulkan on Valve Index at 120Hz

Help here, after the last update it was working flawlessly to me with Vulkan, at 120hz on Valve Index, now I can't play it with vukan unless I take my headset to 90hz, but if I set it to OpenGL, it works on 120Hz, with a lot of re projection but it works.

My setup is: I7-8700k @ 5.1Ghz, 64Gm of RAM 3200Mhz, RTX 2080 TI, Samsung 970 Pro M2, Asus Rog Max X Wifi and Valve Index HMD.

setting it to Vulkan at 120hz, I get a strange stuttering where everything keeps jumping around, only at the headset, because if I look at the monitor it looks good.

It is happening on all scenery.

OpenGL Graph:

Vulkan Graph:

tm.log

main.zip

Just to add here, I checked again with the new nvidia driver today 441.20 and it looks a little better, not much better but it's better, and also running it with FPSVR today I was able to notice that the CPU looks ok, always below 7ms, but the GPU just fluctuates heavily between 120FPS and 9FPS and 57% re-projection.

Also the GPU is away with low ms...

not sure what is going one, is there any other captures that I can yo here to help you out on the diagnosis of this?

Thanks,

Quote from Jet-Pack

Have you tried switching from Steam VR to the "other vr" option?
Did you change any other GPU settings, e.g. in any of the NVIDIA tools? Resetting them to default might yield better results...

Just tried Oculus VR, same behavior.

About the setting on Nvidia Control Panel, yes, have already reset it to default.. no change.

But I'm still launching it from Steam, are suggesting to launch it from somewhere else?

I was doing some further testing today, and happen to notice some scenery flaws that were not ther before, like the top of buildings being stretched of the entire city.

I'm considering on re-installing FS2 from scratch if you find that useful, have already re-installed SteamVR and Nvidia drivers from scratch, the only thing that remains is FS2.

And if you find that it could help, please just let me know how to remove every peace of it before re-installing.

Thanks again.

Totally reinstalled FS2, same behavior.

Overclocking the GPU and setting max FPS (in sim settings) to 120FPS seems to have made it better.

the most strange is when it has to re-project frames I get a lot of black frames....

Quote from Jet-Pack

Hi, can you please upload a few screenshots or photos taken with a camera where we can see the issue?

Yes, both Videos with OpenGL and Vulkan Sorry about the bad quality.

Since the videos are larger than 1Mb I had to place them online, you can find them on the following link: "https://imgur.com/a/JfeghWe"

Quote from ZoSoChile

I think that running Aerofly at 120hz VR would be very stunning. But isn't it kind of expected to have a performance hit at 120hz? Thats alot of pixels to push. Unless I'm just out of the loop with my 90hz headset. But even then I run motion reprojection in some areas.

It does hit 120Fps with my setup, but something odd is happening when it's set to use Vulkan, check out the short videos that I posted and you will see that it works on OpenGL.

Quote from Jet-Pack

That almost looks like defects in the tracking system, sensor being blocked or something?

Do you have any of these issues in other VR software?

No issues with any other games or software, and both videos were taken with the headset at the same position, so you can see that I don't have those gaps when running it with OpenGL.

ok, Just an update here.

The problem is definitely with the reprojection when running on Vulkan.

I just tried setting legacy reprojection mode, and it worked fine without the awful stuttering, a lot of reprojection, way worse than running with OpenGL but playable..

Ok guys, who fixed the problem? Were you with yesterdays update, or was it nvidia with 441.34 driver which states that they have a fix for "[Red Dead Redemption 2] Vulkan: Stalling on some systems with 4-core and 6-core CPUs" which is exactly the same problem that I was having with FS2.

Please let me know if you changed anything with the Vulkan on the last patch, or if you did not, then let me tell Nvidia that they fixed this as well...

This is how it's showing up after both updates (NVidia Driver and your update):

Quote from admin

On the Beta channel we did indeed change something in our Vulkan renderer, but it should have no influence on what you have described.

So, it not clear yet if it was what you changed, or the NVidia update, what I find odd, it that I started to see this problem after NVidia releases the 441.20 Driver, and you released a smal update with Vulkan improvements at the same day, than I tried to rollback the NVidia driver to the previews version and see no change.

Now NVidia releases a new driver that is supposed to fix the same problem on a different game, and you also release a small update at the same day... and now it looks to be fixed..

So, I'm really lost here on what was going on, and who fixed it..

I'll run more tests tonight and let you know if I find anything odd, also if you want any kind of logs or data in order to try to track this down, just let me know what to provide..

ok, just tested it on 3 different scenery, Key West working perfectly, Chicago (Orbx Scenery) working perfect, New York, still having a lot of black frames when re-projection kicks in, but it's far better that it was before..

Ok guys, thanks for your inputs so far, but I'm giving up. last SteamVR update made everything worse than it was before, and by the responses that I'm getting here, looks like no one else is interested on this.

So, good luck with you SIM, I can't play with it anymore...

Quote from ZoSoChile

I don't think anyone else is really running 120hz on this sim so that's why you might not have any feedback from other users.

Few questions?

Is 120hz the deal breaker? Why not enjoy it at 90hz? Or is that glitchy as well?

I wouldn't give up unless you enjoy other flight sims in VR.

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You might be right... I have been spending a lot of time on X-Plane lately, X-Plane doesn't get even close to 90Fps in VR but I can run it at 120Hz because I don't have the same breaks when Re-Projection kicks in...

It works flawlessly at 90Hz, but the feeling and the immersion of the 120Hz is just amazing..

I wish only the devs could have a look into this and give some direction...