DCS Rendering low FPS - Possible software issue

[SatThuVoBui]

I am noticing that DCS is only rendering approximately half the frames set in my graphics.lua file in game. For instance, if I have the maxfps line set at 60, I will run only 30-38 in game. This observation is consistent with 120 and 180 as well. Right now my file is set at maxfps = 60 and I am only pulling an average of 35 frames with my GTX 1080. I therefore thought to set my fps cap at a high value, such as 400. Predictably my frames did go up as a result of it but the issue still remains that each time DCS does this bug my game horrendously stutters and results in unsmooth; choppy gameplay even with nvidia g-sync on.

 

What is interesting to note is that when I enable nvidia shadowplay with maxfps set to 60, my frames increase from the 35 average to 60 - right at the fps limit. I attempted uninstalling nvidia geforce experience to test and see if that would resolve my issue, but unfortunately it did not. This leads me to conclude that there is a software issue in the DCS code or a directX 11 issue going on somewhere. To rule out the potential that I may be experiencing a hardware issue I benchmarked my PC using 3dmark, prime95, and furmark. I did not notice anything out of the ordinary, and my GPU and CPU temperatures do not seem unusually high either, as I did not go above 70 degrees at full load.

 

My in-game DCS settings were everything at low settings, in-game v-sync off, and g-sync on. I tried manipulating those trying out a different combination of each yet every time I still ended up with the same result - approximately 30-35 fps at maxfps = 60. At this point, I'm bummed and cannot figure out for the life of me what could possibly be the issue. I would seriously appreciate any assistance that I can get as I want to resume flying my planes as soon as possible, especially with the release of Harrier :cry:

 

Thank you all very much. Attached are screenshots of my in-game settings and frames with nvidia overlay and MSI afterburner. My specs are listed in my signature. I have a powerful GPU, 16GB of RAM, an i7 6700K, and am booting DCS from an SSD, therefore the issue isn't long loading times. It's entirely software/graphics driver related I am sure.

 

EDIT: If it helps, I would like to add that during these tests my TrackIR was OFF. Was not running simultaneously with DCS.

Edited December 9, 2017 by SatThuVoBui
Addition of information

[msalama]

A driver issue most likely. Download and install NVidia Inspector if you haven't already and check if the driver has its internal FPS limiter set on.

[ellutscho]

I have read some posts about this issue in this forum lately. it seems to be that dcs ignore the preset fps value somehow and limit the max. performance of the gpu. Hope for a fix with release of 2.5.

[SatThuVoBui]

A driver issue most likely. Download and install NVidia Inspector if you haven't already and check if the driver has its internal FPS limiter set on.

 

Just tried that. There appears to be no such fps limit on the driver level. I don't experience abnormally low frame rates on any of my other games so far. This is why I think it's an issue unique to DCS. This is my only game that has this issue.

[SatThuVoBui]

Okay. I've got an update. Upon monitoring my CPU clock speed, I found that while DCS is running my CPU isn't running at a constant 4.2 ghz speed as it should be, but is instead fluctuating between 0.8-2.5-3.0-4.2 ghz. I tested out other games to see if it does the same thing, but it is not the case. This is only happening in DCS.

[petsild]

You can try Control panel - Power Options change to High performance.

[MadDog-IC]

Okay. I've got an update. Upon monitoring my CPU clock speed, I found that while DCS is running my CPU isn't running at a constant 4.2 ghz speed as it should be, but is instead fluctuating between 0.8-2.5-3.0-4.2 ghz. I tested out other games to see if it does the same thing, but it is not the case. This is only happening in DCS.

 

In my travels with DCS over the years and most recently, I have found that pc manufacturers are throttling cpu and Gpu processors to keep heat down, whilst this is great for longevity, it can cause poor game play.

 

Mostly arcade base games, with terrific graphics and little to no physic calculations will run extremely well, as they will load a single core or multi core processor enough to make the cpu ramp up to its maximum GHZ rating and stay there, the same for the GPU, it will engage its cores to process the extreme graphics.

 

By comparison, DCS does not, it is a completely different best, so if your system is mainly a gaming rig you will want to change your power management profiles for CPU and Graphics card GPU to run at their maximum GHZ ratings and never throttle down to anything lower.

 

The more any processor throttles (even for micro seconds) the more stutters and issues you will see in DCS, the closer you can get your processor to a fixed setting of 4 - 5 ghz the better it runs, same for the Graphics card make sure it is running at a fixed highest GHZ rating and or its Boosted rating.

 

You can set the minimum and maximum CPU throttling values in the standard windows power profiles and for a nvidia graphics card, you can set profiles for individual games to disallow throttling in its own nvidia control panel under 3d settings -> Program Settings -> Digital Combat Simulator (Blackshark) -> Power Management Mode = Prefer Maximum performance.

 

Regards, Ian.

[SatThuVoBui]

In my travels with DCS over the years and most recently, I have found that pc manufacturers are throttling cpu and Gpu processors to keep heat down, whilst this is great for longevity, it can cause poor game play.

 

Mostly arcade base games, with terrific graphics and little to no physic calculations will run extremely well, as they will load a single core or multi core processor enough to make the cpu ramp up to its maximum GHZ rating and stay there, the same for the GPU, it will engage its cores to process the extreme graphics.

 

By comparison, DCS does not, it is a completely different best, so if your system is mainly a gaming rig you will want to change your power management profiles for CPU and Graphics card GPU to run at their maximum GHZ ratings and never throttle down to anything lower.

 

The more any processor throttles (even for micro seconds) the more stutters and issues you will see in DCS, the closer you can get your processor to a fixed setting of 4 - 5 ghz the better it runs, same for the Graphics card make sure it is running at a fixed highest GHZ rating and or its Boosted rating.

 

You can set the minimum and maximum CPU throttling values in the standard windows power profiles and for a nvidia graphics card, you can set profiles for individual games to disallow throttling in its own nvidia control panel under 3d settings -> Program Settings -> Digital Combat Simulator (Blackshark) -> Power Management Mode = Prefer Maximum performance.

 

Regards, Ian.

 

I just tried out your suggestion, but unfortunately it did not work. What it did do was force my CPU to run at 4.2 ghz and my GPU to run at its own respective max, but my in-game frames were still sitting around 30-40 fps with the same settings as outlined above. This is leading me to believe that the order of causation is the opposite. DCS isn't running poorly because of a lower clock speed. There is another issue that's causing this to happen in the first place. It's worth noting, I suspect, that as DCS is running there is no icon in the lower windows task bar when I alt+tab out. Is it running as a background application or something, and therefore not being focused on by my PC?

[Mustang]

Have you tried pressing Left Alt + Enter to enable true Fullscreen mode? My FPS halves to 30 every time unless I do this.

[SatThuVoBui]

Have you tried pressing Left Alt + Enter to enable true Fullscreen mode? My FPS halves to 30 every time unless I do this.

Yes I have. It had no affect.

[Goa]

I am noticing that DCS is only rendering approximately half the frames set in my graphics.lua file in game. For instance, if I have the maxfps line set at 60, I will run only 30-38 in game. This observation is consistent with 120 and 180 as well. Right now my file is set at maxfps = 60 and I am only pulling an average of 35 frames with my GTX 1080. I therefore thought to set my fps cap at a high value, such as 400. Predictably my frames did go up as a result of it but the issue still remains that each time DCS does this bug my game horrendously stutters and results in unsmooth; choppy gameplay even with nvidia g-sync on.

 

What is interesting to note is that when I enable nvidia shadowplay with maxfps set to 60, my frames increase from the 35 average to 60 - right at the fps limit. I attempted uninstalling nvidia geforce experience to test and see if that would resolve my issue, but unfortunately it did not. This leads me to conclude that there is a software issue in the DCS code or a directX 11 issue going on somewhere. To rule out the potential that I may be experiencing a hardware issue I benchmarked my PC using 3dmark, prime95, and furmark. I did not notice anything out of the ordinary, and my GPU and CPU temperatures do not seem unusually high either, as I did not go above 70 degrees at full load.

 

My in-game DCS settings were everything at low settings, in-game v-sync off, and g-sync on. I tried manipulating those trying out a different combination of each yet every time I still ended up with the same result - approximately 30-35 fps at maxfps = 60. At this point, I'm bummed and cannot figure out for the life of me what could possibly be the issue. I would seriously appreciate any assistance that I can get as I want to resume flying my planes as soon as possible, especially with the release of Harrier :cry:

 

Thank you all very much. Attached are screenshots of my in-game settings and frames with nvidia overlay and MSI afterburner. My specs are listed in my signature. I have a powerful GPU, 16GB of RAM, an i7 6700K, and am booting DCS from an SSD, therefore the issue isn't long loading times. It's entirely software/graphics driver related I am sure.

 

EDIT: If it helps, I would like to add that during these tests my TrackIR was OFF. Was not running simultaneously with DCS.

 

I am having exactly the same issue, i am running on almost same hardware (expect for gpu as I have a 1080ti), I have tried to cap fps both in graphics.lua and also by creating an autoexec.cfg but i alsways got max fps of my monitor refreh rate (165 hz).

 

Even if I put vsync off/gsync off/ etc etc the game wil be still running at 64 fps, then it goes to 165fps and drop again to 64fps, this happen every few seconds...and I have stuttering as well, with gsync everything should be smooth but no way....tried all combination of vsync on/off/fast , in nvcp, in game on/off but no way......always stuttering and fps drops continuosly from 165 to 64fps.

In other games i dont have any kind of issue , only in dcs the fps fluctuate .:doh:

[docWilly]

Temporary workaround by Mustang:

 

 

https://forums.eagle.ru/showpost.php?p=3327716&postcount=23http://

 

 

Emphasize is on "immediately"....do no wait 10 seconds!!!

[Mustang]

Temporary workaround by Mustang:

 

 

https://forums.eagle.ru/showpost.php?p=3327716&postcount=23http://

 

 

Emphasize is on "immediately"....do no wait 10 seconds!!!

 

Also see this workaround, this one is easier to follow

 

https://forums.eagle.ru/showthread.php?t=198355

[Sideslip]

I noticed your monitor is g-sync capable. There is some odd bug right now (didn't seem to have it a few months ago) where g-sync in windowed mode (even if you aren't running in windowed mode...) screws up framerates. In my case, normal would be 12-20% CPU with 50-80% GPU usage for 60-100fps. When the bug occurs I drop to 8-9% CPU 10-15% GPU and about 23fps with a butt load of stuttering. When g-sync is set to full screen only (not windowed and fullscreen) the bug does not happen at all. This is not a DCS thing, as it happens in IL2 as well.

 

I have the latest drivers, but the reason I updated the drivers was because I was hoping it would fix this issue. My guess is something in the new "creators" update in windows 10 caused this bug.

 

Another stupid nvidia bug is that if you have triple buffering turned on, switching alt-tabing out of the game and back will turn it off. So if your refresh rate is 100hz like mine, normally the fps will be anything (65, 72, 88 etc) and be smoothed by g-sync. However, after alt-tabing it can now only be 100 or 50 (half refresh due to double buffer not allowing it to start working on the next frame until the monitor has been refreshed). So you might think just disable v-sync and it won't happen, but thats not the case. Other than how jittery the screen tearing makes the game look, as soon as you alt-tab v-sync gets turned back on, and now I'm capped at 50fps or 100fps. It's times like this I almost wish I stayed with AMD, if only they had better performance.

 

So if this is your problem, use g-sync only in full screen until they fix the bug and don't alt-tab out of DCS unless you are willing to be capped at half refresh.