Strange VR performance issue

[largecod]

My setup is an Intel 10900K 64gig of ram hero xii motherboard gtx 1080ti 500gig ssd and aReverb G2

My performance has been pretty amazing considering my outdated graphics card.

My current issue is when I load an instant action case 1 supercarrier F14 in Syria the performance is good 45FPS.

If I quit this mission and load the same one again my frame rate drops to 18FPS and its basically unplayable.

If I quit DCS and shutdown PC and restart it goes back up to 45FPS.

Very Strange.

This happens every time without fail.

So the only fix for me at the moment is to restart PC.

I have currently upgraded from an Oculus Rift and dont recall having this problem before.

Has anybody else had this problem?

Hopefully somebody can shed some light.

[Glide]

Your 1080Ti is a great card (same one here) and one of the few that has 11GB of VRAM.  You can get some miles out of it yet.  Check out the posts on turning the Shader Cache OFF in the NCP.  This moves the Shader Cache from disk to memory, and you have room for it with that rig.  Also turn your Terrain Textures to Low for now as there may be issues with higher resolutions and the shader cache.  I run at 4k, and I find this eliminates some stuttering for now.  I am sure improvements are on the way for this issue, but for now many are finding improvements with this strategy. 

 

How much disk space left on that SSD?  Doesn't take long to eat that up if you are running on the same disk as the OS.  I have DCS on it's own drive.

 

Watch out for network or cloud drives.  If you use Tacview,  put your Tacview drive in a location where OneDrive or User Permissions cannot create havoc.  I put them in their own directory on C:.

Edited January 13, 2021 by glide

[largecod]

Hi Glide

Thanks for the tips.

I have just turned off shader cache and will give it a test.

I have 100 gig ram left on my ssd.

Will test and keep you updated.

Thanks again

[Glide]

You will get long loading times at "Wating for Pooled Task 1" the first time you load each map.  If you explode and reload the mission, the second time the load will be short.

[Glide]

These are my settings overall for my 1080Ti, and they are totally AWESOME!  I hope this helps.

[Glide]

BTW, I am not convinced Low Latency Mode = Ultra is the best option.  I see tearing in the cockpit on Ultra.  I have noticed the card works harder when Low Latency Mode = OFF.  I am experimenting with Low Latency Mode = On now.  No tearing so far.

[zildac]

BTW, I am not convinced Low Latency Mode = Ultra is the best option.  I see tearing in the cockpit on Ultra.  I have noticed the card works harder when Low Latency Mode = OFF.  I am experimenting with Low Latency Mode = On now.  No tearing so far.

I'm guessing that particular setting has no impact in VR anyway?

[Glide]

It might be very hard to see on those small VR screens.  Tearing is where you have small slanted lines across the cockpit as the screen draws.  Low Latency = Ultra is supposed to limit predrawn frames to zero.  ON is supposed to be one predrawn frame, and OFF allows frames to queue up.  It makes sense that Ultra would drop the odd frame and cause a tear.  I believe this is similar to Virtual Reality Pre-Rendered Frames.  Leave VR Pre-Rendered Frames at 1 with your CPU because it can feed your GPU easily.  I have the i7-7700 CPU and it's got no problems keeping up.  I think Low Latency Mode might just provide more consistent frame rates by acting like a governor on the pipeline engine.  Let us know if you spot any difference in the G2.  I was running smooth as silk for months before I even noticed this option in an Nvidia truning article. https://www.nvidia.com/en-us/geforce/guides/system-latency-optimization-guide/

 

[divinee]

I’m quite certain that op’s problem is not setting-dependant but caused by the vram leak which has been causing same kind of symptoms since autumn. I’ve had that since the release of syria and i’ve run all possible settings to get rid off it with no help. Even different steamvr versions and nvidia drivers etc. Nowadays i just routinely restart the game after every flight to avoid the fps drop. I’m curious to hear if op finds solution to the problem so i’ll follow this thread but i’m little skeptic before ED improves the vram handling..

[Glide]

I am not sure that thread is conclusive on a VRAM leak.  I think they are saying they "hit a VRAM wall" that drops FPS suddenly, but it seems they cleared it up by taking the weight off the settings.  The OP's problem is very unusual, and I suspect it's disk related.  By moving shader cache up to memory it may solve his strange issue.  Next step would be new SSD so DCS can live on it's own drive. 

 

If VR VRAM handling is broken then its a waiting game for the fix, but I have never seen a memory issue yet. 

Edited January 15, 2021 by glide

[Glide]

Good article on some parts of this stack: https://developer.nvidia.com/blog/nvidia-vrss-a-zero-effort-way-to-improve-your-vr-image-quality/

 

The MSAA Mask option puzzles me.  I don't use any AA in my settings, so would that option be ignored? 

[gunterlund21]

On 1/13/2021 at 7:11 AM, largecod said:

My setup is an Intel 10900K 64gig of ram hero xii motherboard gtx 1080ti 500gig ssd and aReverb G2

My performance has been pretty amazing considering my outdated graphics card.

My current issue is when I load an instant action case 1 supercarrier F14 in Syria the performance is good 45FPS.

If I quit this mission and load the same one again my frame rate drops to 18FPS and its basically unplayable.

If I quit DCS and shutdown PC and restart it goes back up to 45FPS.

Very Strange.

This happens every time without fail.

So the only fix for me at the moment is to restart PC.

I have currently upgraded from an Oculus Rift and dont recall having this problem before.

Has anybody else had this problem?

Hopefully somebody can shed some light.

I have this same problem. If for instance Im in game and go from cockpit to f10 map and back frames drop. If I quit mission and go back in frames drop. Have to leave game. 

[Glide]

Well, I believe there are challenges to the shader cache at the high resolutions needed by VR and 4k.  My settings "minimize the challenges" of the shader cache and let the card go as fast as it can so you have a snowball's chance of getting the FPS you need.  There really should be no difference because the VR headset is just another set of monitors to the video card.  The problem is that VR wants 90FPS at very high resolutions.  That's a tall order from a flight sim. 

[divinee]

My regular settings are quite a close to yours glide, but i still can replicate that fps-drop anyday with about 30% succes rate. When i put the minimum settings, minimum sampling etc, game still makes that fps drop but its more subtle. Shader cache option did no difference except longer cockpit loading times etc.

It's very noticeable that when i spawn at caucasus, vram memory allocation is about 6gb. After first LShift-R (or crashing the aircraft and respawning), allocation goes to about 7gb, then 7,7-7,8 which is maximum and after that the framerate starts to drop and frametimes start to spike until the game is unplayable. After restarting the game vram allocation is back to normal.

[Glide]

That sounds like a leak, and given that it's reproducible ED is no doubt working on it along with the shader cache issue. These issues can't be solved with a settings tweak.  I've got my system running great at 4k, so I know it's going to be fabulous when it's fixed.  I've been spelunking in the old forums on this issue, so I know it's been a frustrating wait for awhile now.  The fixes are coming fast and furious now, so I hope the wait won't be much longer.

[divinee]

Yeah, i noticed great improvement already when november(?) patch came out but there's still lot to do. It won't take long to restart game after every flight so it's still playable. Hopefully it won't take long for ED to fix that because i don't want to fix that probem with 3090

[Glide]

Yeah, the 20 and 30 series are way ahead of the software stacks IMHO.  Flight sims push the envelope and VR is pushing it even more.  These core functions impact the whole community and they are not trivial fixes.  Shader cache changes are huge in terms of hours given the size and quality DCS contains. I think I'm up to 220 GB of goodness now.  

[largecod]

Just an update from my last post.

My bad I dont have to restart PC I just have to restart DCS.

I have tried the shader cache but its made no difference.

This must be an issue with ED since last updates as other members have reported the same issue.

I was thinking about rolling back my nvidia driver to maybe July August last year as from then all updates are tuned for the 3 series cards.

Nvidia probably have no interest now for 1 and 2 series cards.

I have also tested this in 2D.

My frame rates in 2D goes upto 170fps and if I quit the mission and restart is stays the same so obviously the problem is in VR.

So for the time being the fix for me is just to restart DCS everytime I quit a mission.

I have recently downloaded OP Shader and its unplayable.

Starting at Incirik in the A10cII my frame rates are 12fps in VR and a 100fps in 2D.

This performance is shocking but maybe OP Shader is very thirsty.

Glide thanks for your interest but I forgot to ask you,are you playing in VR or 2D

 

 

[largecod]

20 hours ago, divinee said:

I’m quite certain that op’s problem is not setting-dependant but caused by the vram leak which has been causing same kind of symptoms since autumn. I’ve had that since the release of syria and i’ve run all possible settings to get rid off it with no help. Even different steamvr versions and nvidia drivers etc. Nowadays i just routinely restart the game after every flight to avoid the fps drop. I’m curious to hear if op finds solution to the problem so i’ll follow this thread but i’m little skeptic before ED improves the vram handling..

I think spot on.

Nothing to do with settings as I have been using the same settings for over a year.

This problem may have been around since Autumn so could have something to do with nvidia drivers.

I can lower all settings and funny enough I loose FPS,how strange is that.

I think ED problem or nvidia 

[divinee]

17 minutes ago, largecod said:

I think spot on.

Nothing to do with settings as I have been using the same settings for over a year.

This problem may have been around since Autumn so could have something to do with nvidia drivers.

I can lower all settings and funny enough I loose FPS,how strange is that.

I think ED problem or nvidia 

I rolled back to august version of nvidia drivers last week but saw no notable difference. 

[Mustang]

I've mentioned this on another thread but got no response but have any of you nvidia users tried the 465.21 devolper driver?

 

https://forums.guru3d.com/threads/nvidia-465-21-developer.435779/ (see post #3 in link for alternative download location if you cannot log into nvidia website)

 

had this running for a few weeks now and it's been very reliable in terms of stability and performance both in 2D and VR

[divinee]

I have to try that, TY Mustang for the tip!

I managed to backtrack that memory leak a little bit and it seems that if gpu is not using ”shared memory” seen in windows perf tab, all is fine. After shared memory starts to get used like in heavy MP PvE missions or very heavy SP missions, the problem starts.

[Glide]

20 hours ago, largecod said:

Glide thanks for your interest but I forgot to ask you,are you playing in VR or 2D

2D, and I am holding off VR until this gets sorted.

 

I have been wondering if the shader issue and the VRAM leak are related.  If the size of the shader cache stays constant on disk, then DCS may be creating creating shaders erroneously and leaving objects behind in memory. 

 

As I mentioned in another thread, I can make stutters on demand launching to Beirut runway and turning my head back and forth toward the city with HIGH terrain textures.  However, those stutters do not occur if terrain textures are LOW.  I am wondering if those stutters are leaving behind some orphans in VRAM and/or the cache.

 

Could someone with the G2 perform the Beirut test?

[Glide]

8 hours ago, divinee said:

I have to try that, TY Mustang for the tip!

I managed to backtrack that memory leak a little bit and it seems that if gpu is not using ”shared memory” seen in windows perf tab, all is fine. After shared memory starts to get used like in heavy MP PvE missions or very heavy SP missions, the problem starts.

I should mention that in light of this excellent observation, my Beirut test mission is a fully built mission with no real ground action (a few units holding positions, no movement) but a very nice dogfight.  I'll try this again on a blank (smaller) mission.

Edited January 16, 2021 by glide

[zildac]

19 hours ago, Mustang said:

I've mentioned this on another thread but got no response but have any of you nvidia users tried the 465.21 devolper driver?

 

https://forums.guru3d.com/threads/nvidia-465-21-developer.435779/ (see post #3 in link for alternative download location if you cannot log into nvidia website)

 

had this running for a few weeks now and it's been very reliable in terms of stability and performance both in 2D and VR

Tried this today after I saw your post. Seems stable (RiftS VR) no noticeable improvement but tbh I wasn't having any specific issues with the latest public driver on a 3090. Not tried in 2D as yet