Static weather causes stuttering

When it comes to stuttering in DCS there can be a million different causes but one thing is for certain - static weather causes stuttering and dynamic weather does not. I know this has been mentioned on the forums before by others so I decided to test it for myself. Here are the results-

I setup a simple mission on the SOH map with 41 units present. I'm cruising in the F/A-18C at 25000 ft for approximately 7 minutes over heavy cloud cover. I turned on FPS logging in MSI Afterburner and observed the results.

In the first test, I had static weather settings with clouds set to 8 with rain on and winds at 10 knots. Many stutters were recorded with the worst dip was from 60 down to 40 fps. These are major stutters.

In the second test I used a dynamic weather profile I setup that has heavy clouds, winds and rain. The results speak for themselves. I'd like the dev's to recognize this as an offical bug and hopefully fix it. I bet a lot of the complaints about suttering are because of this.

+1 Appart of disappearing clouds bug, since 2 years now. In fact, I edit manually most mission just to enable dynamic weather to prevent stuttering

+1 Appart of disappearing clouds bug, since 2 years now. In fact, I edit manually most mission just to enable dynamic weather to prevent stuttering

It's kind of shocking the difference dynamic weather makes. The problem is that configuring it is not as easy as it should be. I recommend people setup a few different dynamic weather profiles and save them for use in place of static weather.

The other thing that annoys me is how the cirrus clouds are programmed to fade in and out every few minutes. There are some simple things like that could easily be fixed. The addition of some hi-res cirrus cloud textures would improve the look of the sim at the same time.

This guy did a fantastic tutorial on how to create custom dynamic weather profiles. It's a pain but it's worth it for the performance difference.

is static weather also causing stutters with no cloud coverage selected?

is static weather also causing stutters with no cloud coverage selected?

No. Didn´t noticed anything

No. Didn´t noticed anything

I tested this as well and didn't get any stuttering until I added static weather clouds at level 5 to 8. I didn't test full overcast.

So, the problem appears to be with the clouds. For some reason the same clouds added through dynamic weather run perfectly fine.

Adding some more test results. The issue is reproducible in the "Stable Release" version 2.5.3.24984 also so I suspect this has existed for some time.

Here is my test flight in F/A-18C over SOH map. Static weather clouds set to level 8. Flight time is 7 minutes.

I tested this as well and didn't get any stuttering until I added static weather clouds at level 5 to 8. I didn't test full overcast.

 

So, the problem appears to be with the clouds. For some reason the same clouds added through dynamic weather run perfectly fine.

In full overcast there is no stutter. Stutter is only related to static clouds when "disappearing", I think that when the engine take out the clouds, then stutter happens. This is not happen with dynamic weather, in fact with dynamic the clouds doesn´t disappears

In full overcast there is no stutter. Stutter is only related to static clouds when "disappearing", I think that when the engine take out the clouds, then stutter happens. This is not happen with dynamic weather, in fact with dynamic the clouds doesn´t disappears

I suspected no issue with overcast so thanks for confirming. For now I'll be using dynamic weather. I just learned that CombatFlite can also generate dynamic weather conditions and it's super easy to use.. great work-around until ED fixes this.

https://www.combatflite.com/

Does anyone know if there's a way to control the cloud base level with dynamic weather? The default seems to be around 8000 ft and I haven't found any way of changing that yet.

I had post before that are somewhat related. At mission start with static clouds and a bit heavy mssion, try the F2 views until you get to far away aircraft, then back to yours. You’ll get about 8 fps or smoother game play. But if you do too much F2 views the clouds will be less to clear sky when you get back to cockpit view.

I suspected no issue with overcast so thanks for confirming. For now I'll be using dynamic weather. I just learned that CombatFlite can also generate dynamic weather conditions and it's super easy to use.. great work-around until ED fixes this.

 

https://www.combatflite.com/

 

Does anyone know if there's a way to control the cloud base level with dynamic weather? The default seems to be around 8000 ft and I haven't found any way of changing that yet.

Is there a way to get a proper weather briefing when using dynamic weather ? Metar/ TAF?

After days of testing and developing a mild obsession I finally found a workaround for this issue. It turns out the problem is related to the dreaded DCS memory management and seems to get worse with heavy cloud levels set in static weather settings.

In my testing I tried everything from changing DCS settings (shadows, view distance, MSAA level, etc.) to 9 different Nvidia drivers going back to Nov. 2017 to page file vs no page file. Nothing seemed to make a difference in the stuttering. Then I remember reading on the DCS forums once that hitting F11 a bunch of times helps with stuttering...

With preload radius set to max, I cycled through F11 views for all 27 air bases and then watched the RAM perf counter in RTTS go up to nearly 19 GB. Then I started my test which is just a camera view floating above the PG map, 400 knots @ 20,000 ft. for 7 minutes with cloud level 8.

Here are the results.. nearly a perfect 60 fps all the way though. Without doing the F11 cycle I get dips of fps into the 30's as noted in my previous graphs.

Now here's the interesting part. After restarting DCS I still get good results in my test scenario even without doing the F11 cycle. Notice the RAM usage is half of what it is in the first test. Whatever the F11 cycling does sticks through a restart of the game. I suspect it goes away after restarting your PC though.

Sooo, you did not end up doing the F11 thing?

Sooo, you did not end up doing the F11 thing?

:doh: One thing I had forgot to try apparently. Honestly I kinda thought of it as another DCS performance myth but this one turns out to actually work. If anyone doesn't believe it proof is here.

I think this really highlights the continued issues with DCS memory management.

I think this really highlights the continued issues with DCS memory management.

Good findings! Hopefully the devs can work with that.

Cycling through F11 (or F2 if there are units far enough from your starting spot with weather set) just makes static weather clouds to disappear… and so the stutters.

So there is no real magic in relation with F11 isn't it ? It's just like disabling a "heavy" cloud static weather coverage ?

Cycling through F11 (or F2 if there are units far enough from your starting spot with weather set) just makes static weather clouds to disappear… and so the stutters.

 

So there is no real magic in relation with F11 isn't it ? It's just like disabling a "heavy" cloud static weather coverage ?

It loads objects and textures into physical memory. I'm going to post a new thread shortly with testing results on this. I found some new tricks to avoid the disappearing clouds after cycling F11.

I found some new tricks to avoid the disappearing clouds after cycling F11.

Any news on that? Since i also get the flickering water with dynamic weather, i am interested in this workaround for the dissappearing cloud thing...

(my oh my... the weather in dcs is a mess!)

A nice thing I discovered to use the F11 trick and not muck up your static weather- Create an empty mission where you cycle through the F11 views on the desired map. Then save a replay track of that mission.

The next time you start DCS you can just run the replay track prior to loading your real mission. Then you get the affect of having things loaded into memory to reduce stuttering but you don't lose your static weather clouds immediately.

I also found that setting preloadRadius = 0 in the options.lua will allow DCS to use all of your system RAM and GPU memory.. this is interesting for testing. It eliminates stuttering on an empty mission. As soon as you load a mission with lots of AI units it maxes out and will crash if you have your pagefile disabled. With pagefile enabled, it will continue to run but doesn't work as well as F11 cycling + pagefile disabled in my experience.

nice find, bandit!

however, i can't really use your workaround, because i get halfed performance whenever i load into a mission a second time without restarting the game.

i will now try to change the preload-radius though - maybe a lower setting will help me with that particular problem.

memory management is ridicously broken since 2.5, i feel (maybe it was even before that, but then it did not show at least).

nice find, bandit!

 

however, i can't really use your workaround, because i get halfed performance whenever i load into a mission a second time without restarting the game.

i will now try to change the preload-radius though - maybe a lower setting will help me with that particular problem.

 

memory management is ridicously broken since 2.5, i feel (maybe it was even before that, but then it did not show at least).

Actually, I think whatever sticks in memory and reduces stuttering with this, survives restarting the game. If you restart your PC it will be gone of course.

I did forget to mention, I tested preload radius and I see little to no difference between the lowest setting of 100 and highest setting of 150000. The manual states this setting is supposed to preload objects into system RAM so you should see increase in RAM usage with a higher preload radius. This does NOT happen. I'm currently running preload radius set to 100 and have my pagefile off in Windows. With 32GB system / 11 GB GPU this is getting the best results for me currently.

If you force preload radius to zero in options.lua, then it uses all available memory. In my case it would go up to 32 GB of system RAM and 11 GB of GPU memory. If it was empty mission it would run fine like that but with a lot of AI units the game would crash unless I enable the page file.

Maybe I just need 128 GB of system RAM and 32 GB of GPU memory and the game will run great!? :lol::lol::megalol:

Just wanted to confirm, F11 cycling causes clouds to completely disappear, along with any cloud related stuttering.

I was reading the WMR thread and saw Nineline talking about the SteamVR loading screen from time to time using his Odyssey quite a while back.. and I think this is the cause, as it's the only time I experience it myself. Using my monitor it's a stutter.. periodic momentary freezes of the client. Any mission involving static clouds. I haven't dug into the cloud density settings of each mission I might fly with this stutter.. but I'm inclined to think its within the range mentioned previously within this thread.

+1 Please ED fix this. And make this subject a TOP priority. Flying is about weather and clouds, not only land.

Static weather has been bugged since years. I have to edit many missions just to put dynamic weatehr (without stutterings and without cloud disappears at 50 Km).

I suspected no issue with overcast so thanks for confirming. For now I'll be using dynamic weather. I just learned that CombatFlite can also generate dynamic weather conditions and it's super easy to use.. great work-around until ED fixes this.

 

https://www.combatflite.com/

Curious, can you edit existing missions and easily switch them to "Dynamic Weather" with CF or is it just for building missions?