CPU frame time is very high (22ms) in VR on MP servers only and in VR only causing stutters

[darkman222]

I am posting here instead of in the MP section, because this happens in VR only. I am using a Pimax 8KX and a Ryzen9 5900x with a RTX 3090 and 32 GB ram. So I cant invest in better hardware at the moment, given the fact that this system already should be on the upper scale. Settings are almost everything on "low"

Since we are running DCS 2.7 performance overall dropped for me. But especially on MP servers. The problem is that the CPU frame time goes up a lot. Bottlenecking my GPU. Causing stutters in VR.

In the video you can see that I try to lower the resolution in Pitool and DCS to 0.5 and even down to 20% in SteamVR. But the CPU load stays the same. In the end of the video, I took the track file and played it "offline" as mission from the mission editor. You can see now that the CPU frame time is good enough to have a smooth experience. Of course you can see the stutters in VR only and not on the monitor.

This happens in VR only. If I connect in 2D, without VR and the Pimax connected, I get CPU frame times of 5ms. Wich would be absolutely awesome for VR.

Has someone an idea what to do about it? Why is the output in VR combined with MP gaming eating up so much CPU performance?

 

Edited November 3, 2021 by darkman222

[SharpeXB]

In VR the game needs to draw two scenes since it’s running in 3D. That load to draw the extra frames is on your CPU which is why that’s the bottleneck. In MP there are lots of other aircraft and objects to draw, hence even more load. DCS is also essentially single threaded so the main thread of your CPU will bottleneck the system. 

[Enduro14]

It’s more than that, the last couple updates have crushed fps in some folks rigs.  May be another experiencing this performance issue.  

  Have a read through this thread folks with best machines money can buy have a drop of 20fps in same scenarios compared to previous version.  For me I can’t even come close to running same settings and clarity I had before these updates.  But yes multiplayer or campaigns are the true hogs in dcs 

[Ready]

7 hours ago, Enduro14 said:

It’s more than that, the last couple updates have crushed fps in some folks rigs.  May be another experiencing this performance issue.  

  Have a read through this thread folks with best machines money can buy have a drop of 20fps in same scenarios compared to previous version.  For me I can’t even come close to running same settings and clarity I had before these updates.  But yes multiplayer or campaigns are the true hogs in dcs 

For VR the MP missions are a drain. When we play with a few squads together I always notice the faster planes finishing up and jumping out of the server to debrief because my frames improve and stuttering dissapears. Also with the latest DCS updates some important mod were impacted with huge FPS loss as a result. 

[darkman222]

Thanks for pointing out that thread. 14 pages about it already. Gotta go through that.

I think its a combination of graphics improvement and MP. Also almost all servers start to use the new clouds now. Which are nice of course, but they seem to add to the FPS loss with around 15 to 20 % too. It seems that all adds up. I also have the feeling that the clouds syncing between client eats up MP performance through higher CPU loads.

Servers that performed very well before 2.7 became now unplayable.

Edited November 4, 2021 by darkman222

[DavePastry]

hey there! I was having this issue all of a sudden and fixed it by correcting some of my NVCP settings as advised in this comment: 

 

[Annapolis81]

Are you using Microsoft 11?  If so, you may want to check the power management settings for your Universal Serial Bus controllers in Device Management.  The upgrade reactivated power management on all of mine-- including NVidia and 3.1.  Deselecting them won't solve all of your stuttering problems but it did improve some of my VR issues.

[darkman222]

No. I am using W10.  I just checked it anyway. This option seems not to exist in W10. After all it does seem that its not only me having issues, regarding that 17 page long thread about performance loss by other users.

I'll try to see if some of the tips in the thread DavePastry pointed out could help in my case.

EDIT: Tried it, I already had everything as suggested in the thread.

 

Edited November 8, 2021 by darkman222

[darkman222]

But the main question, beside that VR causes higher CPU load than playing in 2D is why does multiplayer add so much CPU load too?

[RealDCSpilot]

I guess we have to wait until the engine overhaul with multicore enhancements is ready.

[SharpeXB]

On 11/9/2021 at 8:16 AM, darkman222 said:

But the main question, beside that VR causes higher CPU load than playing in 2D is why does multiplayer add so much CPU load too?

Multiplayer can simply have more objects than a SP mission which in some cases can be very simple. Some MP missions have a great number of ground objects or units in addition to the players who’s number can get quite high as well. Otherwise I don’t know that there’s any fundamental difference between MP and SP performance. 

[darkman222]

I suspect the amount of objects (vehicles, clouds, stationary objects) that need to be synced between clients affects performance. A dogfight server that ran smoothly before 2.7 has a significant higher CPU load now, since the server started to use clouds, which also need to be synced between clients. Unfortunately that additional amount of CPU load the 2.7 update created, made CPU frame times so high that its not a smooth ride for me any more. But the same server has a BVR area whith less players in it and players being not as close together, which is still kinda okay performance wise. So I guess less players in the closer area around my own aircraft causes less syncing between client machines. Obviously the clouds were an additional thing that has to be synced for every player.

Another dogfight server did not start to use the new clouds and the performance drop 2.7 gave was not as significant. Just occasional stutters. Almost like before the 2.7 update.

I guess thats how it is. DCS evolves hardware comsumpsion rises with it. Fingers crossed that Vulkan and multicore optimization will optimize the performance in the future.

Edited November 11, 2021 by darkman222

[A2597]

Oh thank goodness I'm not alone!

I havn't been able to fly for a few weeks, and finally had an evening, only to be in single digit FPS on the ground, and low 10s when flying low.

Spent the past two hours troubleshooting, only to see that it's a known issue. *whew!*

[darkman222]

So I have a theory. First we got the new smoke und flame effects. They look like some kind of volumetric, non sprite/ bitmap based technology.

When we had this, but no clouds yet, I realized when there were lots of players shot down, and lots of those smoke trails were in my sight, my CPU was slowing down. Because the smoke effect has to be synced between clients. When the amount of smoke got less, the CPU frame time recovered.

Then we got the new clouds and frame time jumped up in general. Of course GPU demands were rising too, but fpsVR shows that my system is still capable of the clouds GPU wise.

Also there are 2 similar dogfight servers out there. One with and another without clouds. With a comparable amount of online players on the one without clouds the CPU performance is still okay.

Edited November 20, 2021 by darkman222

[darkman222]

Forget about what I said above. I was on that server again. Bad CPU frame time. After a few minutes I watched the replay through the headset. The EXACT same stutters and CPU frame times ocurred during the corresponding phases of the replay. I was remembering them because I was just a few minutes online on the server.

If I could remove the clouds temporarily in the replay I could check if they are causing the issue too and do further investigation.

Edited November 21, 2021 by darkman222

[dureiken]

Hi

did you find some tips to improve that ? I have really bad cpu frametime when playing liberation campaign with some friends, only in VR.

 

Thanks

[darkman222]

I gave up. In fact its a known thing in the game industry. As hardware gets more capable the software and games get more hardware demanding to deliver a better experience and visuals. Same for DCS. My hardware was on the edge for the Pimax 8KX. Development goes further to 2.7 and my hardware cant keep up any more.

I hope that EDs multiprocessing optimisations and Vulkan API will do the trick at some time for me. If not, well then I need to wait for better hardware and upgrade the rig whenever hardware development makes the next huge leap and it makes sense to purchase better hardware.

Edited December 15, 2021 by darkman222

[TED]

There is no way your performance should be that bad. I’m running lower cpu and gpu, 3800xt and 6900xt, and have no problem in mp. Makes me wonder if something in your windows settings or even bios settings is slowing the system down. Did you check all the process priority settings in task manager? Perhaps something or several things there are running in high priority and drawing power. Make sure dcs and vr are set on highest priority and everything else within reason low or disabled. 
I assume you have a decent psu and your system is not powering down due to power supply. The last thing I’d check is your internet connection. Run a speed test and if u r using WiFi try using a wired connection instead. I was having these issues a while ago and it was all down to my internet. I was in a 2.5 ghz connection. Switched to 5ghz and problem solved. 

[darkman222]

I tried a lot... Reinstalling, CPU overclock GPU overclock. Reinstall again etc. VR shader mods. Installed 1000W PSU. Never used a Wifi connection. I have the fastest connection available where I live.

Rember, I am on a Pimax 8KX which is a not really common headset. And my investigations found that even if I lower the SS resolution to 0.5 I still have high CPU frame times. It seems that the fact that as soon as DCS 2.7 has to render (or the CPU has to prepare images) for both eyes CPU frame time drops A LOT. I can run DCS MP in 2D 3440×1440 resolution with ridiculus low CPU times like 5 ms, often less.

Also depends on how the MP mission is setup. There is a non updating MP dogfightserver called "just dogfight" without clouds, maybe old scripts which are not so sophisticated but CPU friendlier. That server often is playable until more than 3 players show up simultaneously. There is a newer server called "DCS dogfighters" with clouds, newer scripts for sure. No matter how little players are online its just a stutter show for me. CPU frame times go up to 16 ms - 20 ms ....

 

Edited December 15, 2021 by darkman222

[dureiken]

Could we test with a miz or track ? could be nice to compare between us, and to ask ED some help if it's not a computer problem

 

Thanks

[EvilBert VR]

Hey darkman,

that sounds really really strange! What GPU driver are you using? Your system should easily be able to handle the 8KX with satisfying settings.

As you can see in my signature, I am operating 2 different systems with using an even more demanding headset from time to time. I never faced any of your issues EXCEPT when I was tweaking the RAM on my DDR4 board. But optimizing the system and also checking the LTs on the RAM solved my problem with the DDR4. To be honest: I never really found out what caused the step on the brakes. But neither did I care since everything was just fine afterwards.

Have you checked your background tasks when running DCS? 

Cheers
 

[dureiken]

Hi

I just made a test track, from liberation. I am clearly CPU bound (12600k@5ghz + 3080 ti +32GB DDR4); CPU frametime around 18-20ms  all the time and when I go on the runway looking heading 070 (near the frontline) I have 30ms in CPU frametime.

When I am in the plane with VR, when I look at EAST my CPU frametime goes up instantly.

Could some of you test the same track, specially the end ?

https://www.mediafire.com/file/ozrkiat557ic6yh/Test_Liberation.trk/file

Thanks

Edited December 15, 2021 by dureiken

[darkman222]

I tried your file. CPU time on the ground does not make too much sense to compare in my opinion. It its always very high. I did not even play through your file as I already had like 40 ms on the taxiway and I got some script errors right on the start.

You can try this file here. https://www.dropbox.com/s/rzarmvnuz6ld4j4/mobettameta's Dogfight Arena v1.26-20211215-230047CPUframetime.trk?dl=0 Its from the dogfight MP server. Very short replay. CPU time goes up before I shoot the F18 which is very close. That is the live CPU frame time in the fpsVR graph. The second one after the short black screen is from the track replay when a distant ground of 3 bandits appear. Also like 18ms CPU time.

Again Ryzen9 5900x and RTX 3090 on my end.

See the video:

 

Edited December 16, 2021 by darkman222

[RED]

@darkman222@dureiken What is your "idle" cpu frame time? What do you get just opening an empty map? Below 10ms with no spikes? Do you have a prebuilt with any software running or any rgb stuff etc in the background?

[dureiken]

1 hour ago, RED said:

@darkman222@dureiken What is your "idle" cpu frame time? What do you get just opening an empty map? Below 10ms with no spikes? Do you have a prebuilt with any software running or any rgb stuff etc in the background?

Yes I often have under 8ms with empty map

 

could you test my track in VR and tell me your CPU frame time ? thanks