[performance] Trees - huge performance hit especially up close

[Bucic]

TLDR: I finally discovered why my performance dipped so badly compared to just 2 months back.

My system is 100+ FPS capable. Usually capped at 60 FPS. First I've noticed I can no longer fly 50+ FPS over Marianas. I just thought its looks has been ramped up and ignored it. Then I started to notice stuttering while flying low level. It turns out it's not just stuttering.

As it is now DCS turned from 100+ FPS to almost unplayable, just like that. Especially that switching from DLAA to MSAA x4 didn't change the situation by even a bit. Just a reminder: MSAA is basically completely broken anyway in the current build.

I included a modless track file but also recorded a video on a separate flight to show you what I'm seeing. I doubt track files contain performance metrics of original player's flight and nVidia recording has negligible impact on performance on my system.

 

Specs:

1440p LG UltraGear 27GP850-B G-Sync
Intel i3-12100F

RTX 2070 8GB MSI, latest nVidia studio driver 32.00.0015.6636 (English)  Driver Version: 32.0.15.6636

64 GB RAM

Motherboard MSI PRO B660M-A WIFI DDR4 (MS-7D43)

2024-12-19 18:39:54.538 INFO    APP (Main): options.graphics =
{
    ['volumetricLights'] = 1;
    ['AA'] = 'DLAA';
    ['forestDetailsFactor'] = 1;
    ['rainDroplets'] = true;
    ['LensEffects'] = 0;
    ['box_mouse_cursor'] = false;
    ['anisotropy'] = 4;
    ['water'] = 0;
    ['maxfps'] = 59;
    ['motionBlurAmount'] = 1;
    ['BlurFlatShadows'] = 0;
    ['outputGamma'] = 2.1;
    ['aspect'] = 1.7777777777778;
    ['lights'] = 2;
    ['LODmult'] = 1;
    ['MSAA'] = 2;
    ['messagesFontScale'] = 1.25;
    ['canopyReflections'] = 1;
    ['width'] = 2560;
    ['visibRange'] = 'High';
    ['DLSS_PerfQuality'] = 1;
    ['useDeferredShading'] = 1;
    ['clutterMaxDistance'] = 0;
    ['textures'] = 2;
    ['cockpitGI'] = 1;
    ['terrainTextures'] = 'max';
    ['height'] = 1440;
    ['multiMonitorSetup'] = '1camera';
    ['shadows'] = 4;
    ['defaultFOV'] = 55;
    ['shadowTree'] = false;
    ['chimneySmokeDensity'] = 10;
    ['secondaryShadows'] = 0;
    ['SSS'] = 0;
    ['fullScreen'] = true;
    ['preloadRadius'] = 61200;
    ['scaleGui'] = 1;
    ['Scaling'] = 0.66;
    ['DOF'] = 0;
    ['clouds'] = 1;
    ['sceneryDetailsFactor'] = 1;
    ['Upscaling'] = 'OFF';
    ['Sharpening'] = 0.7;
    ['motionBlur'] = 0;
    ['ColorGradingLUT'] = 0;
    ['SSLR'] = 0;
    ['effects'] = 3;
    ['SSAO'] = 0;
    ['maxFPS'] = 60;
    ['sync'] = true;
    ['heatBlr'] = 0;
    ['forestDistanceFactor'] = 1;
    ['flatTerrainShadows'] = 0;
    ['civTraffic'] = '';
    ['ScreenshotExt'] = 'png';
};

 

Track and log (as usual, dxdiag dump only on demand via PM):

https://1drv.ms/f/c/66cf2646234394fc/EkB24ygz9mBLqN6BJlpqAMoBauptRXW6rOmTCLgQXMurkg?e=CEWV8j

Edited December 19, 2024 by Bucic

[scommander2]

Is it happened due to recent release?  Or, few releases back and gradually?

[Raven (Elysian Angel)]

Might as well have put your report in the Game Performance Bugs instead, then there would have been no need to add the [ performance]  tag  

https://forum.dcs.world/forum/483-game-performance-bugs/

Nothing changed when it comes to trees as far as I'm aware: the last change was the switch to Speedtrees, and that was quite a few years ago.

[Vee.A]

What happens if you turn forest details factor down?

[Bucic]

43 minutes ago, scommander2 said:

Is it happened due to recent release?  Or, few releases back and gradually?

I went from some ~May build straight to December.

[Lixma 06]

I have a sneaking suspicion one reason we haven't yet seen a Vietnam map is because of the horsepower needed to render all that jungle.

 

 

[scommander2]

Could it be VRAM maxed out?  What was the GPU metrics from task manager since MT-CPUs ran very low.

[Bucic]

10 minutes ago, Lixma 06 said:

I have a sneaking suspicion one reason we haven't yet seen a Vietnam map is because of the horsepower needed to render all that jungle.

 

 

A sensible studio adjusts techniques to available computing power. Not the other way around. ED's choice to cling to rendering of individual (and overlit beyond reason) trees even for forests is of their of their own doing.

 

39 minutes ago, Raven (Elysian Angel) said:

Might as well have put your report in the Game Performance Bugs instead, then there would have been no need to add the [ performance]  tag  

https://forum.dcs.world/forum/483-game-performance-bugs/

Nothing changed when it comes to trees as far as I'm aware: the last change was the switch to Speedtrees, and that was quite a few years ago.

As far as I know SpeedTree is a model generation toolkit, not a rendering technique. Also, there's no reason to assume the performance drop is an outcome of a deliberate implementation. Same as with the broken MSAA.

[YoYo]

I've been flying with 0.5 LOD in trees for a long time. It completely solved the performance problem for me, and I don't really see any difference honestly.

[Bucic]

1 hour ago, scommander2 said:

Could it be VRAM maxed out?  What was the GPU metrics from task manager since MT-CPUs ran very low.

Not likely. 6500 or even ~7000 was nothing out of the ordinary on my system still at 100 FPS.

Could you please clarify your question on GPU usage? My system always runs "GPU limited" with DCS.

EDIT:

The GPU utilization is ~90% and the temps rise rapidly.

Edited December 19, 2024 by Bucic

[Bucic]

20 hours ago, YoYo said:

I've been flying with 0.5 LOD in trees for a long time. It completely solved the performance problem for me, and I don't really see any difference honestly.

That's (almost) besides the point. I'm comparing the same hardware and DCS configuration to just ~2 updates back. There's clearly some choking happening universally with trees. I don' t have an issue with bringing the tree LOD down. I just wouldn't want a performance issue of the infamous Lock On flares caliber to slip under the radar and grow into a permanent performance issue component of low discoverability.

Edited December 20, 2024 by Bucic

[Viper33]

11 minutes ago, Bucic said:

That's (almost) besides the point. I'm comparing the same hardware and DCS configuration to just ~2 updates back. There's clearly some choking happening universally with trees. I don' t have an issue with bringing the tree LOD down. I just wouldn't want a performance issue of the infamous Lock On flarescaliber to slip under the radar and grow into a permanent performance issue component of low discoverability.

Welcome to DCS. It's been a constant performance degradation for me as well over the years.

[Bucic]

OK, I've just confirmed 100% similarity of my current vs pre-December updates configuration. That includes both in-DCS and in-nVcpl settings.

To better illustrate the problem, compare the DCS performance metrics (notice the frame time sawtooth pattern!) between the scene where barely a 1 km radius is visible in the scene vs the other shots. The last screenshot I took deliberately at the exact moment the distance to the trees corresponds to start of the performance dip.

https://1drv.ms/f/c/66cf2646234394fc/EkB24ygz9mBLqN6BJlpqAMoBauptRXW6rOmTCLgQXMurkg?e=CEWV8j

Edited December 20, 2024 by Bucic

[Bucic]

1 hour ago, YoYo said:

I've been flying with 0.5 LOD in trees for a long time. It completely solved the performance problem for me, and I don't really see any difference honestly.

The frame times turn into sawtooth even with LOD set to 0.1 and Tree Visibility Slider turned down almost to minimum. It seems that the bug is triggered MAINLY by the close proximity to trees. The only required factor is: the trees are out of the lowest LOD. That's it.

[Vee.A]

I have noticed that effect. Depending on tree settings it can take a good 50% or so of FPS. No stutters, just raw FPS. But I recall having that issue for a very long time, so I'm not sure if it's specifically a new bug or not.

[maks]

Also shadows is conflicting with fps! From normal to flat no problems

[Bucic]

1 hour ago, maks said:

Also shadows is conflicting with fps! From normal to flat no problems

I had them set to Normal since I bought the RTX 2070 with no such problems. For now I'm going to just use the LOD set to minimum or even force some lower value in the graphics settings lua file.

[scommander2]

5 hours ago, Bucic said:

the LOD set to minimum or even force some lower value in the graphics settings lua file

Thanks for testing and sharing the experience.  I did experience of losing 5-9 FPS when LOD=1 as default.

[Bucic]

1 hour ago, scommander2 said:

Thanks for testing and sharing the experience.  I did experience of losing 5-9 FPS when LOD=1 as default.

Could you please set LOD ~0.7 or whatever and look at the frametime metric graph while getting very close to the trees?

[Vee.A]

9 hours ago, maks said:

Also shadows is conflicting with fps! From normal to flat no problems

I tested default versus flat with the trees on max and got a 20FPS difference.

[scommander2]

On 12/20/2024 at 4:14 PM, Bucic said:

Could you please set LOD ~0.7 or whatever and look at the frametime metric graph while getting very close to the trees?

Set LOD=0.7 and 0.1 and fly low, my FPS does not get any improvement (my both NCP and DCS maxFPS=60). 

[jnr4817]

I have same issue with trees and new buildings in iraq.

[Bucic]

7 hours ago, scommander2 said:

Set LOD=0.7 and 0.1 and fly low, my FPS does not get any improvement (my both NCP and DCS maxFPS=60). 

So that would confirm the bug. I managed myself to trigger it even with LOD 0.3. Like I said before, as soon as "non-minimal" LOD is in view, the performance dives dramatically, with sawtooth frametimes. It's worth realising that as soon as you hit sawtooth frametime on a graph, FPS don't matter anymore. That characteristic is indicative of a serious performance problem where a game engine will not and cannot deliver any satisfactory end user experience as it turns itself into a heat virus, akin to Prime95 "benchmark".

Edited December 22, 2024 by Bucic

[scommander2]

9 hours ago, Bucic said:

So that would confirm the bug.

Thanks!!

[Bucic]

I plea to have this bugs triaged together. In specific conditions a single object in view sinks the entire game performance.

trees - December 4th update, or maybe earlier as it was difficult to notice

F-5E - December 24th update