GPU Usage bouncing all over the place in VR

[Justin1Ntime]

HI quick question. I have a 3080TI and Quest 2 set on RR 1.6. I have semi high settings in DCS. I notice that my GPU usage is bouncing from 95% to 47%. it looks like a sawblade when I look at the stats after my game is over. When GPU usage sinks so does the frame rate. I go from 60FPS to 35FPS. its bouncing all over the place. When I play other titles it pretty much stays at 90 - 100 percent usage for most of the game. Does anybody know what is going on here? 

[edmuss]

Sounds like there is a bottleneck that is happening with a regular frequency; possibly something talking to the CPU in the background.

What are the CPU and GPU frametimes doing when it happens? If you're using steamvr, grab a copy of fpsvr or if you're using open composite/openxr toolkit use the built in performance overlay.

Any winwing hardware or antivirus without the DCS folder set as an exclusion? Could it also be the oculus link bottlenecking because you're running really high resolution? What's the rest of the system?

Edited July 26, 2022 by edmuss

[speed-of-heat]

The other thing that can cause this is a somewhat unstable over volt, where you don't quite have enough voltage to keep the power stable...

[Justin1Ntime]

14 hours ago, edmuss said:

Sounds like there is a bottleneck that is happening with a regular frequency; possibly something talking to the CPU in the background.

What are the CPU and GPU frametimes doing when it happens? If you're using steamvr, grab a copy of fpsvr or if you're using open composite/openxr toolkit use the built in performance overlay.

Any winwing hardware or antivirus without the DCS folder set as an exclusion? Could it also be the oculus link bottlenecking because you're running really high resolution? What's the rest of the system?

 

I have. a I7 6600 Skylake processor. Its quite a few years old and I have it overclocked to 4.6Ghz from 4.2Ghz. I have 32 Gb of Ram running XMP Profile  on Windows 10. It could be QuestLink,I didnt think of that. I wonder if I try to switch to Air Link maybe that might help too. I think I need to figure out how to use OpenXR toolkit. I have never used that before. I will also try to turn down the RR and see if that helps. Maybe set it back to 1.0. I will give it a try tonight.  Oh yeah I am running DCS standalone. I did not purchase vai steam. 

1 hour ago, speed-of-heat said:

The other thing that can cause this is a somewhat unstable over volt, where you don't quite have enough voltage to keep the power stable...

I took all overclocking off of my GPU and that didnt make a difference

Edited July 26, 2022 by Justin1Ntime

[edmuss]

I would suspect that it's your CPU that's holding everything back.

If it's an i7 6600u then it's a 2c/4t part which isn't enough really for DCS. The 6600u was the only i7 6600 I found in my quick search and it's a laptop CPU. As you said you overclocked it I suspect you might have an i5 6600k

If it's an i5 6600 then it's a 4c/4t part that will handle it better but it's not leaving much overhead unfortunately. DCS will happily use three threads.

DCS VR is unfortunately very CPU intensive and it will essentially mean that your very expensive GPU is sitting idle waiting for information

I'd look to grab a Ryzen5xxx and motherboard, keep the RAM and GPU and you'll see a world of difference

Edited July 26, 2022 by edmuss

[Justin1Ntime]

Yeah, its long overdue for an upgrade, that is for sure. I was just waiting on the new Ryzen or 13th Gen CPUs to come out before pulling the trigger. Its an 4 core 8 thread processor. Its a 6700 I think. I know its Skylake. 

[edmuss]

Well the new Ryzens are supposed to arrive next month I think but will need new ram as well as they're moving to DDR5.  Depends on your budget really

[Dragon1-1]

Do check if it's not some background process hogging the CPU, this might well be unrelated to DCS. Something like Windows trying to scan the whole damn filesystem to make sure you're not trying to disable its updates, or your AV being brain-dead. I'm CPU-limited, too, but my FPS is smooth, and the last time I had something like that happen, it was some Windows BS. 

[Justin1Ntime]

13 hours ago, Dragon1-1 said:

Do check if it's not some background process hogging the CPU, this might well be unrelated to DCS. Something like Windows trying to scan the whole damn filesystem to make sure you're not trying to disable its updates, or your AV being brain-dead. I'm CPU-limited, too, but my FPS is smooth, and the last time I had something like that happen, it was some Windows BS. 

Yep that was the first thing I did. Regardless of what is open, the settings GPU usage just bounces all over the place. I tried airlink same result. I tried turning down my RR and changed the quest back to 72hrz, while I saw an overall reduction in GPU usage it still bounded all over the place not exceeding 50% with settings this low. I then said well let me crank it up and to 1.7 which is max with 120hrz and same results on GPU utilization except it was more in the 90% then drop to 50%. I did notice that I am using 12.2 GB of Vram and my card only has 12 so I am not sure if that might be a problem. I am thinking its my very old CPU or maybe its just the game and this is the way it behaves. Check out the picture. 

[Dragon1-1]

Possible, but I have another question: how much RAM do you have, and are you running off an SSD or a HDD? It's possible what you're seeing is the OS paging RAM to HDD. If you don't have a whole lot of RAM, and/or a slow storage such as a HDD, DCS will bog down even if all your other hardware is adequate. SSD is practically a requirement for DCS, I saw a huge FPS increase once I switched. I really didn't think that it'd have such an effect. Likewise, upgrading from 8 to 16GB of RAM got rid of some nasty stutters.

[Justin1Ntime]

12 minutes ago, Dragon1-1 said:

Possible, but I have another question: how much RAM do you have, and are you running off an SSD or a HDD? It's possible what you're seeing is the OS paging RAM to HDD. If you don't have a whole lot of RAM, and/or a slow storage such as a HDD, DCS will bog down even if all your other hardware is adequate. SSD is practically a requirement for DCS, I saw a huge FPS increase once I switched. I really didn't think that it'd have such an effect. Likewise, upgrading from 8 to 16GB of RAM got rid of some nasty stutters.

I have 32GB system and 12GB Vram. I am running on a M.2 500GB drive dedicated only to this game. I had it on my M.2 with windows but due to the size of the game, I dedicated a drive just For DCS as I ran out of space. 

[edmuss]

It could be lack of system ram, try running memcleaner in the background and see if it alleviates your issues

 

[Justin1Ntime]

Its for sure not a system ram problem as I am not coming even close to maxing that out. 

[edmuss]

Are you sure? 32gb doesn't last long in DCS and once windows starts getting towards RAM capacity it will start using page file.

[M1Combat]

Definitely try the memcleaner as Edmuss suggests...

Also try to get us concurrent traces for the CPU like you posted above for the GPU.

Currently this -

Appears to my eye to point to CPU issues because (and I'm assuming here...) it's all normal looking for in sim world stuff, then I think you probably exited to the menu/hangar screen which is where the drops to 0 happen, then...  it kicks back in but to much more usage on the GPU as before...  indicating that the CPU wasn't holding it back as much...  as you'd expect in the hangar.

So...  Get us the CPU traces along with GPU traces and I think we'll find it's a CPU issue...  but...  exactly what issue will depend on the frequency of the peak/valley trace of the CPU.  If it up and down like this GPU trace it's probably normal.  If it's up and down at a much lower pace...  maybe cooling or something?

[5ephir0th]

I would bet its just ASW kicking in, with that hardware and insanely high resolution you are always with ASW on at 1/2 framreate (thats why you have 60 fps at 120hz, ASW as another step, 1/3, and maybe it kick in when you have low GPU usage cause your system cant mantain 60 fps (that i doubt it can)

Try 72hz and lock it at ASW  45hz and look at the GPU usage, you can try too disabling ASW at 120hz and you should be always maxing the GPU (at least when your GPU its not the limiting factor)

Edited July 27, 2022 by 5ephir0th

[Tomcat388th]

 I'm fairly new to the VR side of thing but I have a low end sytem for DCS t3600 workstatition xeon 3.2GB 32GB ram,SSD drives and a 8gb 1070 and I'm running a quest2 using the openxr runtime with the oculus traytool.  SP mission I'm getting around 35-40 and MP 20-35  using airlink. Even though its low frame rates my dcs is smooth granted I had to back off some of the graphics settings for my system. I'm flying the hornet and can read everything just fine. I have my quest at 90H 1.0 and in DCS vr page set to .5.  and my tool tray settings.  When using airlink for me 0 on both bitrates got me the best gameplay.  I hope you get it figured but I thought I would post my settings if it might help down the road

J

 

[Justin1Ntime]

Thanks for the response guys, I will work on getting that done. With that being said, any recommendations on a New CPU? Mine is so old and I was going to replace it anyway so I will start there. Should I be looking at the AMD 5800X3D or Intel 12th Gen I7? I only use this system for gaming. What is the best CPU for VR and DCS. Also is this the toolkit I should be using with Oculus? https://mbucchia.github.io/OpenXR-Toolkit/

[speed-of-heat]

my 12700k runs well... 

On 7/26/2022 at 9:24 PM, Justin1Ntime said:

 

I took all overclocking off of my GPU and that didnt make a difference

 

one thing i have also seen , is that even the native clock might need an undervolt to get a stable clock speed... 

[Tomcat388th]

1 hour ago, Justin1Ntime said:

Thanks for the response guys, I will work on getting that done. With that being said, any recommendations on a New CPU? Mine is so old and I was going to replace it anyway so I will start there. Should I be looking at the AMD 5800X3D or Intel 12th Gen I7? I only use this system for gaming. What is the best CPU for VR and DCS. Also is this the toolkit I should be using with Oculus? https://mbucchia.github.io/OpenXR-Toolkit/

No that is not it or at least I never could get it to work with my quest2 .Go back one page where you started this post and goto to page one of this topic "OpenXR Guide for WMR Headsets"   I did steps 1-5   its got the links for downloads. After you get that installed and when you start the oculus program there will be a message on top stateing your not using oculus runtime ignore it. For the toolkit do a google search for oculus tray tool   https://www.apollyonvr.com/oculus-tray-tool that is the program that I posted images of. When you do the changes in traytool hit save and restart sometimes it will come up with msg say that it cant restart or close something just hit save and restart again and it should go and then it will restart the oculus program. For dcs I boot up the headset then start traytool once it up minimize it then fire up airlink and then dcs. My traytool setting are what I use for airlink have no idea if their good or bad with the link cable.  Also to the experts here and not to hijack this thread if there anything I could be doing to squeeze out any performance or improvement please give me your thoughts

thank you

J

Edited July 28, 2022 by Tomcat388th

[edmuss]

CPU wise I would look at Intel 12th gen or wait for the Ryzen7xxx to be released. The 5800x3D is awesome but also on a mostly dead platform (AM4) so only really worthwhile if you're already invested in AM4.

I went from a Ryzen 5 3600 to the 5800x3D and it gave me around 25-30% more performance on an already well optimised machine and saturated GPU.

[Justin1Ntime]

On 7/28/2022 at 11:58 AM, edmuss said:

CPU wise I would look at Intel 12th gen or wait for the Ryzen7xxx to be released. The 5800x3D is awesome but also on a mostly dead platform (AM4) so only really worthwhile if you're already invested in AM4.

I went from a Ryzen 5 3600 to the 5800x3D and it gave me around 25-30% more performance on an already well optimised machine and saturated GPU.

Thanks, I am thinking the same thing, I will just try to be patient and wait till the release of Ryzen7 and then make a decision. 

[M1Combat]

On 7/28/2022 at 6:24 AM, Justin1Ntime said:

With that being said, any recommendations on a New CPU? 

I didn't look at your specs but will anything newish plug into your current motherboard?  Do you have an AM4 board?

[edmuss]

He's on an i7 6700 so not a lot that will slot in and make much meaningful help I don't think

[Justin1Ntime]

On 7/30/2022 at 5:50 AM, M1Combat said:

I didn't look at your specs but will anything newish plug into your current motherboard?  Do you have an AM4 board?

I agree with edmuss. Not much can be done with the MOBO. Its just too old. Its time for an upgrade. The 6700 has been good but its time