I pinned the performance killer! Its Fauna, turn it off!

[ждун]

I have tuned my setting in VR so it runs stable smooth at minimum 40 fps so I can reproject up to 80 Hz without artifacts. Im having 40 fps (80 reprojected) everywhere, even over new york during storm. Well usually, but i have noticed something weird. Over rural area, where is actually not so much to render, sometimes the performance starts tanking temporarily. Dropping to 30 or below. But only sometimes and after a while it goes away. Then I have noticed it is somehow dependend on which direction I am looking. When I look out the left window it tanks, out of the right window its smooth. So I have suspected it is something specific that causes it. Then I finally figured that out. When it started tanking again I was looking towards a field where some cows were grazing. Looking away in the other direction no problem, but looking at that field and the performance dropped again.
I have turned OFF fauna in the settings, and voila, never seen this happen again!
Previously I had it on LOW btw but it was still killing the performance.
Turn that OFF if you experience occasional performance drops.

[Heynettc]

Good suggestion, i will try it because in VR, i have the same issue than you. Drop of fps when i change the direction of my view...

[Heynettc]

works perfectly too for me, now my fps are stable during the flight for every directions of my view, thanks

[Mightylink]

Sounds like a bug with fauna spawning, I've seen it in other games. There's probably thousands of moose or something spawning under the runway.

[ждун]

I don't know whats wrong with it, but the performance suffers when there is wildlife around. I heard they took the animals from some zoo game, perhaps they are not yet properly optimizied for the sim.

[Twelvefield]

That's right: the animals are from Frontier's zoo game.

[Trigger_Trim]

Originally posted by ждун:

I have tuned my setting in VR so it runs stable smooth at minimum 40 fps so I can reproject up to 80 Hz without artifacts. Im having 40 fps (80 reprojected) everywhere, even over new york during storm. Well usually, but i have noticed something weird. Over rural area, where is actually not so much to render, sometimes the performance starts tanking temporarily. Dropping to 30 or below. But only sometimes and after a while it goes away. Then I have noticed it is somehow dependend on which direction I am looking. When I look out the left window it tanks, out of the right window its smooth. So I have suspected it is something specific that causes it. Then I finally figured that out. When it started tanking again I was looking towards a field where some cows were grazing. Looking away in the other direction no problem, but looking at that field and the performance dropped again.
I have turned OFF fauna in the settings, and voila, never seen this happen again!
Previously I had it on LOW btw but it was still killing the performance.
Turn that OFF if you experience occasional performance drops.

Dude! I have been going insane the past few days trying to nail down my stuttering issue in VR since the latest patch. I've done literally everything to try and fix it. I would put my graphics settings in VR all the way to low-end and it would make no difference at all. I would just get this constant stuttering. I knew it wasn't my hardware, my graphics card and CPU were both far from max usage. As a last ditch effort today, I wiped my hard drive and completely re-installed windows 11 and installed nothing but my graphics card drivers (RTX3090 TI) and steam/FS2024 and steamvr. I started the same flight I've been testing with, and after a very short period of nice smooth flying (false sense of hope there), stutters came back.. Just like you said, it seemed to worsen as I would look around. I stumbled on your post just a bit ago and said, what the heck, I've tried everything else. I went in, changed literally nothing other than set Fauna to "off". and started up my same flight again. Like magic, I just spent the last 30 minutes flying in almost completely stutterless bliss! There are still some stutters every now and then, but like, maybe only 5% of what they used to be. This is SOOO much better. Thank you for noticing that, and taking the time to post about it! I hope ASOBO sees this and looks into the cause and gets it ironed out in an upcoming patch.

[Ikarus 👾]

i pinned the performance killer, its asobo

[Trigger_Trim]

Originally posted by Ikarus 👾:

i pinned the performance killer, its asobo

this, as opposed to the OP post, is stupidly not helpful

[TargetLost]

Didn't work for me :(

Most studder I have in Europes Northern Airports. Started at EDDV.
Fauna disable didn't help. So I reenabled it.

Sometimes during the long taxing it recovered despite me looking always in the same direction.

There was a lot static planes... I suspect that it is the streaming in general and Fauna is maybe a lot data to stream.

[ждун]

@TargetLost
The performance impact from fauna seems not to be streaming related. I also suspected streaming to be the problem, but I was observing my network and discovered that performance issues with fauna were also present when network was idle. So fauna definetelly puts some pressure I assume due to lack of optimization.

Now your performance issues may be related to something else on top. If I may give you an advise that is worth checking. From what you describe I would guess you could suffer from VRAM overflow. This is another common problem that can cause severe performance problems. The background is if the sim needs to allocate more video memory than is available, it starts swapping to regular RAM, which is like 100 times slower than the ultra fast GPU memory. When your PC drops into that state you experience massive performance breakdown and severe stuttering until some video memory is cleared and it fits again into available GPU memory. This is a safety mechanism that is supposed to prevent the sim from crashing (even though it does sometimes anyway in that state).

It is also well possible to run into VRAM overflow even when you have a high end GPu with plenty of VRAM available, as there are memory leaks in the sim. For example I have noticed that some planes, like the pilatus PC-6 will always sooner or later run into VRAM overflow no matter how much you have available. There is obviously a memory leak. There could lso be memory leaks in the scenery in certain areas.

To verify if you have VRAM overflow, you can use a variety of tools to monitor VRAM usage. I am using a tool that is called "GPU Temp" which is a lightweight tool that is for monitoring GPU temperature, but it also allows to monitor VRAM usage. I would suggest when you experience performance break down to check if your VRAM usage has approached close to 100%. When this is the case it is very likely that your GPU is already in overflow state and is using some of your RAM, which would explain the performance issue.

To avoid that problem it can help to reduce rendering resolution, terrain lod or texture quality. But this only helps if that is not coming from memory leak. A memory leak is obvious when VRAM usuage keeps growing over 100%. In that case there is not much you can do, but maybe use a different plane if it the memory leak is aircraft related or fly at different places if it is scenery related.

Hope it helps.

[TargetLost]

Makes sense. Thank your for the hint.

Maybe I also simple have to reboot the flight sim more often.... the last day I started it in the morning and had it running all day doing one flight after anohter. It is really that stable for me.

[Twelvefield]

I don't doubt that fauna are a problem, but unfortunately they are not the complete problem. After the update, I get plenty of stutters on the ground which go away when I am in the air and come back when I am on the ground again. Then too, sometimes the stutters go away on their own. I suspect a ground texture shader, that was a big problem in FS20.

[ждун]

on the ground tress, gras, plants and rocks pop up in high quality, which puts additional pressure on the hardware and performance goes down to certain degree expectably. Especially when these are set on high or ultra quality the impact is of course more significant. Have you checked VRAM usage level? It could be that you are just over the fence when you are flying and just dropping below max available vram when higher lod trees and gras is in the scene? When this is the case, well I would reduce quality for those. Also in this particular situation dynamic quality feature helps actually, it reduces the lod levels automatically when you fall below certain fps which you can set, which doesn't hurt as when youre on the ground you aint really have much qualty gain from high terrain lod for example.

Another thing worth trying is clearing shader cache. Look it up how to do it, outdated shaders in the driver cache indeed can cause performance problems. It is always a good idea to do that after updates. So for example if there was a change on shaders in an update, but your GPU would prefer using the compiled shader in the cache instead, which may become unstable and and cause problems. Perhaps try that.

In the latest update they have upgraded DLSS version from 2.7 to 3.7, if your performance problems are as you say since latest updates, and youre also using DLSS I would definetelly recommend trying clearing the shader cache.

[Twelvefield]

I'm not having memory problems, my flights are short and not prone to that kind of thing. Clearing out the shader cache is a good thought, though. I used to do that for 2020. My understanding was that nVidia fixed that corruption bug, but who knows, it could easily have come back.

[ждун]

ps: here is a short guide on clearing shader cache for nvidia cards
https://portkeygamessupport.wbgames.com/hc/en-us/articles/14659998310803-How-To-Clear-Your-Shader-Cache