The Ocasional FPS Drops In Full Fidelity Aircraft

[FierceLV]

Hello Pilots.

While flying the Digital Combat Simulator World (not MT), I have encountered a weird problem.

First I had an overall poor performance of the DCS World, it was solved with the help of the DCS World Community. The problem was in Windows 10, the system was parking CPU cores, it was solved by the utility named ParkControl.

Overall performance of the PC has greatly improved, in every game. Thank You for that.

Now onto the issue of this topic:

1. I use only keyboard for flying, no mouse (like in the first Lock On - Modern Air Combat, the Classic).

2. I use Object Local Camera configured as the static Chase Camera (looks like in the Ace Combat series, but feels much better because of the superb DCS World flight model).

The built-in Chase Camera shifts the screen during turns of the aircraft, I find it very annoying, and I lose sense of control of the aircraft.

3. So while flying like that I am noticing occasional Frames Per Second drop that last like 0.5 seconds. These FPS drops happen when performing high-G turns on full fidelity aircraft.

4. I noticed that the Flamming Cliffs series aircraft almost entirely lack the FPS drops, so this leads to a conclusion that the FPS drops are directly connected with the giant amounts of script that represent the full fidelity aircraft.

So maybe someone can share his experience and shed some light on this issue.

DCS World log while flying the F-15E without enemies in Afghanistan is included. DxDiag also is included. And a screen shot of how the Object Local Camera looks like in the role of the Chase Camera is also included.

With big respect to the Fighter Collection ($$$$$), the Eagle Dynamics, the Friends of the DCS World (Other Studios), and the precious DCS World Community.

Please, help me.

DCS World Log 09.03.2025.log DxDiag 09.03.2025.txt

[rob10]

You may not realize it, but you are on the current version of DCS so you ARE using the MT version (from your log: DCS/2.9.13.6818 (x86_64; MT; Windows NT 10.0.19045) since there is no ST version anymore.  That's not really important to your question though.

Taking a quick look at your log you should set your pagefile to 32GB set max and min value, set it on your fastest drive, and make sure that drive has at least 10% free space (after taking the 32 GB for the pagefile into account).  You've only got 32GB RAM and your pagefile is showing about 4GB so you're almost for sure running out of memory with full fidelity planes.

[FierceLV]

1 hour ago, rob10 said:

You may not realize it, but you are on the current version of DCS so you ARE using the MT version (from your log: DCS/2.9.13.6818 (x86_64; MT; Windows NT 10.0.19045) since there is no ST version anymore.  That's not really important to your question though.

Taking a quick look at your log you should set your pagefile to 32GB set max and min value, set it on your fastest drive, and make sure that drive has at least 10% free space (after taking the 32 GB for the pagefile into account).  You've only got 32GB RAM and your pagefile is showing about 4GB so you're almost for sure running out of memory with full fidelity planes.

Thank you, your suggestion helped a lot. Setting the Pagefile Size minimum and maximum value to 32 GB improved the DCS World performance, as well as PC overall performance.

A follow up question: what is the optimal Pagefile Size minimum and maximum value provided that PC has 64 GB of RAM?

[jackd]

I think you should always set a pagefile on the C drive of i think minimum of 200 or 200O MB as you have a separate pagefile drive (partition) like i have of 64000 MB.

[Flappie]

With 64 GB of RAM, Windows gives a default 4 GB pagefile, which is enough for now.

[FierceLV]

3 hours ago, FierceLV said:

Thank you, your suggestion helped a lot. Setting the Pagefile Size minimum and maximum value to 32 GB improved the DCS World performance, as well as PC overall performance.

My bad...

Setting the Pagefile Size to 32 GB didn't help. I confused the positive effect of it with the performance gain from ParkControl software (still didn't got used to it's effect on the PC).

Setting Pagefile Size to 32 GB didn't have any observable impact. In the Task Manager the used Commited Memory value didn't go above 30 GB, but in fact the maximum Commited Memory value was 64 GB.

As things look at the moment, the issue described in this topic is indeed caused by the lack of RAM, however reducing the Terrain Preload Radius helps a lot, something around 30600.

Thank you for your attention.

 

 

[British_Dragon_14]

I just switched back to 'System Managed' and it chose exactly 28672 MB. It currently says:

Minimum allowed: 16 MB

Recommended: 9066

Currently allocated: 28672 MB

I wanted to reduce my Pagefile size as I now have 64GB's of RAM. My Pagefile was previously set to 40000 MB.

I've also changed 'processor scheduling' to adjust for best performance of: 'Programs.' Instead of 'Background services.' I'm hoping it will reduce stutters.

I also discovered that DCS doesn't like it when I overclock my RAM speed. Even if it's just by + 200 MT/s. I would keep crashing in multiplayer servers at 6800 MT/s and at 6600 MT/s, so I reduced it to stock XMP profile 1. Which is 6400 MT/s.

[silverdevil]

On 3/9/2025 at 5:34 PM, FierceLV said:

My bad...

Setting the Pagefile Size to 32 GB didn't help. I confused the positive effect of it with the performance gain from ParkControl software (still didn't got used to it's effect on the PC).

Setting Pagefile Size to 32 GB didn't have any observable impact. In the Task Manager the used Commited Memory value didn't go above 30 GB, but in fact the maximum Commited Memory value was 64 GB.

As things look at the moment, the issue described in this topic is indeed caused by the lack of RAM, however reducing the Terrain Preload Radius helps a lot, something around 30600.

Thank you for your attention.

hello. are you still having issues?

[FierceLV]

On 4/1/2025 at 12:34 AM, silverdevil said:

hello. are you still having issues?

Hi, yes I do still have issues with the performance of the DCS World.

The F-16C and the F-15E are causing the most issues. The F-16C has worse performance than the F-15E.

The occasional Lag of unknown origin is occurring during high-G maneuvers and during high-speed flight, during fast change of the scene on the screen (when the full sky screen rapidly changes to a full land screen during the high-G maneuvers, or during high-speed flight maneuvers).

I do not know the cause of this phenomena, but from what I understand it is directly interconnected with amount of scene rendered on the screen and the flight model scripts of the full fidelity aircraft being processed during the high-G maneuvers or the high-speed maneuvers. 

Due to the fact that I use the Object Local Camera instead of the built-in Chase Camera (because of the detrimental camera sway of the built-in Chase Camera) the Lag with the F-16C and the F-15E in particular are observable quite often.

I have doubt that the 32 GB of RAM is causing this Lag phenomena to appear, mainly because other full fidelity aircraft (A-10C, AH-64D, Ka-50, Mi-24P) are performing much better than the F-16C and the F-15E, maybe it is because those are the slower flying ones, and the scene on the screen changes less frequently and that there is less high-G maneuvers.

The performance of the A-10C, AH-64D, Ka-50, Mi-24P is such that I can't notice lags even if they still take place.

The Flaming Cliffs aircraft on my end performs flawlessly, high-G or no-G - all the same.

Maybe the Over-G performance of the F-16C and the F-15E is the route cause of the Lag.

But this time I managed to gather some evidence to back up my case.

Some F-15E screenshots and a F-16C short video of less-than-average-quality (<50 MB).

Notice the Lags captured on the F-15E screenshots during the rapid change of the flight regimes.

Just in case, I added the DCS World log and the DxDiag.

Is there any thing else that I can provide in order to help to pinpoint the root cause of this Lags?

dcs 10.04.2025.log DxDiag 10.04.2025.txt

Edited Thursday at 07:09 AM by FierceLV

[silverdevil]

5 hours ago, FierceLV said:

Hi, yes I do still have issues with the performance of the DCS World.

The F-16C and the F-15E are causing the most issues. The F-16C has worse performance than the F-15E.

The occasional Lag of unknown origin is occurring during high-G maneuvers and during high-speed flight, during fast change of the scene on the screen (when the full sky screen rapidly changes to a full land screen during the high-G maneuvers, or during high-speed flight maneuvers).

I do not know the cause of this phenomena, but from what I understand it is directly interconnected with amount of scene rendered on the screen and the flight model scripts of the full fidelity aircraft being processed during the high-G maneuvers or the high-speed maneuvers. 

Due to the fact that I use the Object Local Camera instead of the built-in Chase Camera (because of the detrimental camera sway of the built-in Chase Camera) the Lag with the F-16C and the F-15E in particular are observable quite often.

I have doubt that the 32 GB of RAM is causing this Lag phenomena to appear, mainly because other full fidelity aircraft (A-10C, AH-64D, Ka-50, Mi-24P) are performing much better than the F-16C and the F-15E, maybe it is because those are the slower flying ones, and the scene on the screen changes less frequently and that there is less high-G maneuvers.

The performance of the A-10C, AH-64D, Ka-50, Mi-24P is such that I can't notice lags even if they still take place.

The Flaming Cliffs aircraft on my end performs flawlessly, high-G or no-G - all the same.

Maybe the Over-G performance of the F-16C and the F-15E is the route cause of the Lag.

But this time I managed to gather some evidence to back up my case.

Some F-15E screenshots and a F-16C short video of less-than-average-quality (<50 MB).

Notice the Lags captured on the F-15E screenshots during the rapid change of the flight regimes.

Just in case, I added the DCS World log and the DxDiag.

Is there any thing else that I can provide in order to help to pinpoint the root cause of this Lags?

hello. i know you said you changed your pagefile. however it has reverted.

2025-04-10 06:18:45.351 INFO    APP (Main): CPU cores: 12, threads: 20, System RAM: 32606 MB, Pagefile: 4864 MB

did you switch it back?

i used the dcs log analyzer on your log. see the following:

Advice
 
Please update to the most recent version of DCS World.
Change your pagefile to at least 32768 MB (initial size).
Upgrade your OS to Windows 11 to better support your CPU or disable cores 16,17,18,19 in Windows or Process Lasso
Verify that this is configured correctly in Windows:
Game Mode disabled
Hardware accelerated GPU scheduling disabled

Tuning Tips
 
Consider using DLAA.
Set Shadows to Medium.
Turn down Anisotropic Filtering.
Set Water to Low.
If you have FPS issues, try turning off VSYNC in graphics settings.
Decrease Terrain Textures.
Set Clouds to High.
Tuning tips are recommendations for better FPS based on your CPU, GPU and RAM.
They might result in slightly decreased display quality.

[FierceLV]

2 hours ago, silverdevil said:

hello. i know you said you changed your pagefile. however it has reverted.

2025-04-10 06:18:45.351 INFO    APP (Main): CPU cores: 12, threads: 20, System RAM: 32606 MB, Pagefile: 4864 MB

did you switch it back?

i used the dcs log analyzer on your log. see the following:

Advice
 
Please update to the most recent version of DCS World.
Change your pagefile to at least 32768 MB (initial size).
Upgrade your OS to Windows 11 to better support your CPU or disable cores 16,17,18,19 in Windows or Process Lasso
Verify that this is configured correctly in Windows:
Game Mode disabled
Hardware accelerated GPU scheduling disabled

Tuning Tips
 
Consider using DLAA.
Set Shadows to Medium.
Turn down Anisotropic Filtering.
Set Water to Low.
If you have FPS issues, try turning off VSYNC in graphics settings.
Decrease Terrain Textures.
Set Clouds to High.
Tuning tips are recommendations for better FPS based on your CPU, GPU and RAM.
They might result in slightly decreased display quality.

Hi, thank you for your intention to help me with my problem.

You have suggested many really useful methods to address my problem.

Let us continue with the issue:

1. I play DCS World really simple, I use only the keyboard, no mouse, I have a decent performance-wise personal computer.

2. I do not use any kind of system tweaks that provide inconstant personal computer performance (fluctuating FPS, Overlays, overclocking and things like that).

I aim at the clean and constant performance of the personal computer (things like FPS cap to keep the FPS at one level all the time). I do not use any third-party software or mods, I prefer the "as clean as it gets" approach, "the way it was intended to work".

3. With the help of the DCS World Community, some time ago I have unlocked my CPU cores with the help of the ParkControl software. The ParkControl software improved the overall performance of my personal computer.
However the occasional Lag remained, and the Lag remained mostly in the F-16C and the F-15E.

4. Currently I am not updating the DCS World because the "Campaign Save" function is still too fresh.

5. Regarding the Windows 11: I don't want to upgrade the system, because I have achieved a good performance of the Windows 10.

6. Regarding the PageFIle: I returned it to the default system setting, because there was no performance gain with the DCS World, the system continued to allocate the same amount of RAM for the DCS World.

Personally, judging by my long time observations I can surely (95 %) conclude that the problem of the Lag lies within the aircraft itself, or in the Game itself.

I have managed to pinpoint the exact origin of the occasional Lag during flying the F-16C and the F-15E.

And the origin of the Lag is: THE MOMENT WHEN THE CPU THREADS ARE SWITCHED. This can be easily seen on the video attached to this post.

The Lag itself is the moment when the rendering threads are changed: CPU Bound (Rendering Thread) <- LAG ->  CPU Bound (FPS Limit).

But not always the Lag occurs during the moment when the rendering threads are changed: CPU Bound (Rendering Thread) < --- >  CPU Bound (FPS Limit).

To prove my point I have lowered every visual setting in the DCS World and recorded a video where I provoke the Lag by flying the F-16C high-G.

On the lowest settings the Lag occurs much less often, but still you can cause the Lag to take place.

So the problem lies somewhere in the: RENDERING THREADS (CPU Bound (Rendering Thread), CPU Bound (FPS Limit), CPU Bound (Main Thread), GPU Bound(?)).

While researching the Lag, I have noticed that when the Game rendering is GPU Bound the Game doesn't lag at all, but the GPU Bound rendering doesn't last long for some reason.

But then again, I am not a PC expert, I don't know much about it.

So the problem is somewhere in the performance of the rendering process of the Game.

Now I know it sounds kinda far-fetched since only I am using the Object Local Camera as the Chase Camera, but go ahead and try to fly the F-16C the same way I do, and check if the Lag exists for you.

If the DCS World F-16C or F-15E won't lag for you with the same Local Object Camera configuration during the high-G, that means that the problem is on my end, but if it does lag for you as well, then the problem lies in the DCS World itself.

There is no continue with the issue that I experience until someone tries to fly the F-16C with the Object Local Camera set as the Chase Camera.

How to set the "Object Local Camera" as Chase Camera? Bind actions "Local Object Camera", "Zoom In Slow", "Zoom Out Slow" for the F-16C.
Then chose the "Object Local Camera" in the aircraft list and bind actions Camera Height Up Slow, Camera Height Down Slow, Slow Left Key LCtrl-A, Slow Right Key LCtrl-D.

For example:

    LRCTRL + NUMPAD8        Camera Height Up Slow
    LRCTRL + NUMPAD2        Camera Height Down Slow
    LRCTRL + NUMPAD4        Slow Left Key LCtrl-A
    LRCTRL + NUMPAD6        Slow Right Key LCtrl-D

Load the F-16C on any map, press the "Object Local Camera" key and use the Camera Height Up Slow, Camera Height Down Slow, Slow Left Key LCtrl-A, Slow Right Key LCtrl-D, "Zoom In Slow", "Zoom Out Slow" keys to place the Object Local Camera behind the F-16C. A video of how it looks like is attached to this post.

And check for lags, maybe it is only me who can't fly F-16C with a proper Chase Camera without lags.

Edited Thursday at 03:03 PM by FierceLV

[FierceLV]

I need to be fair, I did not try to turn of CPU Cores 16, 17, 18, 19.

I figure they are some kind of special economical CPU cores. Can some one explain in more detail why exactly it is proposed to disable those cores?

I don't want to alter the default performance of my personal computer, because it might detrimentally influence the overall performance. There are 20 cores for a reason.

[silverdevil]

2 hours ago, FierceLV said:

conclude that the problem of the Lag lies within the aircraft itself, or in the Game itself.

please do not take my comments as an argument but as a hopefully a creative discussion. you seem like a guy with a scientific background considering your detailed explanation.

the empirical data is that you have a computer that was plenty a few years ago. now with all the changes to dcs over those years, our systems are no longer plenty. also, if everyone using dcs were dealing with the same problems as you are, it would not be nearly as popular as it is. there are other items i shared you could change to make the experience better. scientific method has to be employed to make the situation better for you.

with that said, i have a system with 128 GB of RAM, an 11 series CPU, and a 3090 gfx card. i have none of the problems you mention. i do not park cores or any of the other workarounds i see in the forums. there are other things in the tips that you can try too before giving up on it.

and believe me when i say, anything you do to improve the performance of dcs is not going to hinder or have detrimental effect on the overall performance of your computer.