Solution: How to fix stuttering in the Syria map.

[aleader]

On 2/1/2021 at 10:58 AM, fitness88 said:

I'm using a 1080, 32ram, i7-7700k, have graphic settings low in Syria with no stutter. However I would like to be able to turn up the graphics so looking at a new rig with a 3090 card [i9.10900kf, 64ram]. 

Is there a big performance difference between the 3080 and the 3090 [understand the memory difference].

Don't waste your money on a 3090.  Worst GPU ever made for gaming.  Look at the benchmarks.  I have a 3070 and there are still terrain stutters in DCS (at 1440p).  I turned the terrain textures down to low on the Syria map, MSAA 4X, and now it's close to 100 fps, but I have it capped at 75.  It's the game, not the hardware.  A 3060ti will be more than enough, if you manage to find one.  The 3070 is getting more available though (or the 6800). 

Edited February 6, 2021 by aleader

[Lurker]

Why is Sria

5 hours ago, aleader said:

Don't waste your money on a 3090.  Worst GPU ever made for gaming.  Look at the benchmarks.  I have a 3070 and there are still terrain stutters in DCS (at 1440p).  I turned the terrain textures down to low on the Syria map, MSAA 4X, and now it's close to 100 fps, but I have it capped at 75.  It's the game, not the hardware.  A 3060ti will be more than enough, if you manage to find one.  The 3070 is getting more available though (or the 6800). 

 

 

I've got a 3090RTX. Best GPU I ever owned. Let me tell you, for VR it's not even close to being overkill in DCS (And that's on Caucasus)

Edited February 6, 2021 by Lurker

[Glide]

What makes the 3090 attractive is 24GB of VRAM.  This is the holy grail for DCS.  The reason you have terrain stutters is because you don't have enough VRAM.  Tweak your settings such that your 3070 NEVER uses Shared GPU memory, and you will be happy.

[Hoirtel]

On 2/6/2021 at 11:08 AM, glide said:

What makes the 3090 attractive is 24GB of VRAM.  This is the holy grail for DCS.  The reason you have terrain stutters is because you don't have enough VRAM.  Tweak your settings such that your 3070 NEVER uses Shared GPU memory, and you will be happy.

3090 still has stutters on Syria. I get single big stutters, but pretty infrequent so not really a problem. Although I do only have 32gb system mem...

[parxuk]

On 2/6/2021 at 11:08 AM, glide said:

What makes the 3090 attractive is 24GB of VRAM.  This is the holy grail for DCS.  The reason you have terrain stutters is because you don't have enough VRAM.  Tweak your settings such that your 3070 NEVER uses Shared GPU memory, and you will be happy.

 

Hi there. Please can you tell me how you can tweak your settings so that the GFX card doesnt use shared memory?

 

Thanks

[Glide]

2 hours ago, parxuk said:

 

Hi there. Please can you tell me how you can tweak your settings so that the GFX card doesnt use shared memory?

 

Thanks

Textures and Terrain Textures are the two big ones.  There are a few settings, but I can't recall all of them.  Nothing in the Nvidia control panel will help this issue.  If you have two monitors you can leave the Task Manager open to the Performance tab with your GPU selected on one monitor.  

 

Number of units on the mission also impacts this.  For example, a full super carrier group can add 1GB of VRAM usage to each mission.

 

I have never measured Multiplayer. 

 

Maybe we should start a new thread on the secrets of lowering VRAM usage. 

 

[Dangerzone]

Page 19 on the DCS manual says:

 

PRELOAD RADIUS. Radius of the preloaded terrain around user position in meters. A large setting can decrease hard disk swapping but it requires more system RAM.

 

(Emphasis mine)

 

I have 64GB of system RAM, but only 8GB of VRAM. (2080 Super) and I'm running a HP Reverb in VR. With the above I have no idea what I should be setting it to.

 

I'm wondering what others would recommend for my preload radius? (With the manual saying system RAM I feel as though I should be able to bump it up high, but since I only have 8GB VRAM and have heard some people say it's VRAM related and not system RAM I'm not entirely sure). 

 

 

4 hours ago, glide said:

Maybe we should start a new thread on the secrets of lowering VRAM usage. 

 

That sounds like a fantastic idea - and if you do - please post the link to the new thread here!

Edited March 4, 2021 by Dangerzone

[C3PO]

On 2/6/2021 at 2:40 AM, aleader said:

Don't waste your money on a 3090.  Worst GPU ever made for gaming.  Look at the benchmarks.  I have a 3070 and there are still terrain stutters in DCS (at 1440p).  I turned the terrain textures down to low on the Syria map, MSAA 4X, and now it's close to 100 fps, but I have it capped at 75.  It's the game, not the hardware.  A 3060ti will be more than enough, if you manage to find one.  The 3070 is getting more available though (or the 6800). 

 

My 3090 Ultra has made a huge difference in Syria, because of the 24GB of VRAM. No stutters on max settings.

[Worrazen]

Reason for stuttering besides VRAM is also because the engine seems to require some data from disk that it needs to continue execution, I am in the middle of another session of investigating into this, what I have been suspecting for years and that's why the move to SSDs and NVMe for DCS has made a big difference.

 

If this is 100% techncially correct I don't know, whether that's a bug or just how it is, geometry most likely isn't streamed and models have to be fully loaded, that is normal for most such software so what I think is happening is because the assets aren't loaded in the beginning and have to be later on right when they're needed.

 

Another reason for stutters is CPU, because terrain asset (textures) loader threads require quite a bit of CPU and can saturate a lot of cores and this will determine the speed at which your textures will pop-in, so it's not just disk speed and responsiveness.

 

However terrain texture streaming never causes the engine to stop executing, something else is causing that, something that is more random and obscure and I've yet to dig into it. Why I haven't done this yet is because it took some time to peel away all the other sources of stuttering and then isolate and identify the various kinds. I will post a thread to the DCS 2.7 Game Performance Bugs section (unless 2.7 fixes this) in a few weeks or so.

 

The stuttering I'm talking about may not even be noticed by many because it's subtle, a few frames here or there, but still.

Edited March 24, 2021 by Worrazen

[fitness88]

Why does audio stutter occur when graphics stutters how are they connected...what does this indicate, is there a resolve?

I also hear audio stutter at higher FPS.

All this happens when over the Syrian cities.

Resolved:

This only happens when I stream to Bigscreen [VR app] using Bigscreen's audio drivers to allow visitors to hear the DCS audio.  All is good when back using Rift or Realtek drivers.

Edited March 24, 2021 by fitness88

[C3PO]

A plea please: even with a chunky GFX card the VRAM usage in Syria is getting bonkers. Can further optimisations be made? Ignore frame-rate, it’s capped for monitor purposes...
 

Edited March 25, 2021 by C3PO

[Worrazen]

^^ Well higher VRAM usage is infact welcome, to take the load off RAM, so that's probably a good thing. The RAM acting as a second level cache for textures is what probably needs to be tamed slightly.

 

But the system should kinda dynamically detect hardware and adjust this according to specs, it probably does so anyway, but in some configurations perhaps it's a bit too close to the max for comfort.

[lukas_lb]

Hello!

While The map is on sale I think about buying it, but couldnt test the performance yet. While I can run caucasus and PG with playable 45-50fps, the new marianas map is unplayable for me (15-20fps).

Will syria be playable for me with my old rig and medium settings?

CPU: i5 6600

GPU: rx470 8GB D5

RAM: 32GB

Thank you!

 

[Rick50]

 

If Mariannas is struggling on your machine, so will Syria IMO.

[Hoirtel]

On 10/29/2021 at 6:34 PM, Rick50 said:

 

If Mariannas is struggling on your machine, so will Syria IMO.

I have the opposite! I can do low level over any city on Syria just fine. Of I try Guam I get fps loss. For some reason Marianas is heavy going. I actually think Syria is quite good given the detail it has. Channel map is somewhere in between. 

[PravusJSB]

I posted something that might be able to help in this thread: 

 

[Mr_sukebe]

One point on VRAM.  If for example you’re an Oculus user, the Oculus “home” that you see on putting on your headset (ie before even starting DCS) uses something like 1.6GB of VRAM.  Windows uses some more.  So whilst you might have 8GB of VRAM, half of it might already be in use.

If you go into the settings for your headset, do disable the home page and see the effect

[MustangSally]

Lots of stuttering flying over Cyprus with my old 2080ti, now I have the 3080ti it's as smooth as silk.

[Steel Jaw]

On 2/6/2021 at 6:08 AM, Glide said:

Tweak your settings such that your 3070 NEVER uses Shared GPU memory, and you will be happy.

How can I tell when my GPU is spilling over into shared memory, and BTW what is "shared memory" is it RAM?

[Glide]

Hey bro, shared GPU memory is in RAM, but not as fast as VRAM.  It does not get used until the Dedicated GPU memory is full, although there is a small allocation to it when the game launches.  You can have Task Manager running while the game is on.  I only use one monitor these days, so I have to alt-tab to see what's happening in the last few moments.  The graphics on the second monitor get swapped out while the game is in fullscreen mode.  This is handled by the windows desktop manager.

 

[Glide]

On 3/30/2022 at 4:07 PM, Steel Jaw said:

How can I tell when my GPU is spilling over into shared memory, and BTW what is "shared memory" is it RAM?

BTW, Terrain Textures = Low, Textures =Med, Vis Range Low, Terrain Shadows OFF, is a good combo for cards that are short on VRAM.  I haven't seen a stutter in 2d in ages even with my settings.  Haven't tested VR with the latest yet.

[Steel Jaw]

Oh Syria runs fine for me in 2d with TIR but absolutely TANKS in vr

[Glide]

Just now, Steel Jaw said:

Oh Syria runs fine for me in 2d with TIR but absolutely TANKS in vr

Yeah, VR is a holy mess.  I'm waiting for a miracle.  Until then, the headset is just a novelty. 

[Steel Jaw]

10 hours ago, Glide said:

Yeah, VR is a holy mess.  I'm waiting for a miracle.  Until then, the headset is just a novelty. 

No no, VR works pretty well for me in the other maps.

[Dangerzone]

Have you guys considered OpenXR? Not sure what headset you use, but I switched, and bypassing steam with this has made things far more smoother. I'm able to fly in locations that I'd never be able to fly in normally without stuttering.