Stutters - Only close to the ground - disappear in turn

[alexis0391]

Dear all,

 

I’m huge fan of dcs and more specificaly of The m2000c.

 

The issue i have is that when i am close to the ground i have huge stutters which disappear when i engage a turn. There must be something not processed when the aircraft has angle...

 

I have dcs 2.5.5 on a dédicated ssd , i7 4700k , rtx2060 and 16go ddr4 2700 cl15.

 

In altitude Flight i run dcs with 55/60 fps, éven in dogfight.

 

Everything goes wrong Close to thé ground :-(

 

Could you please help me out on this ?

 

Thanks l

 

Alexis

[Sjokkel]

Maybe you could try lowering the clutter/grass and tree settings as a test?

[blayas]

disappears with turn and angle? This really sounds like something related to the radar altimeter

[alexis0391]

Thanks for helping.

 

I just figured out where the problem comes from : vsync.

 

When vsync is ON in DCS, i have a 30 fps when i level off. when i make a turn, stutter disappear and i gain 20 fps back.

 

That's interesting isn't it ?

 

by the way i still don't the answer on why it goes this way

 

Maybe something linked with nvidia gforce xperience ?

 

its weird anyway

[Worrazen]

Draw calls probably increase when you get lower and closer to objects.

[Boosterdog]

Thanks for helping.

 

I just figured out where the problem comes from : vsync.

 

When vsync is ON in DCS, i have a 30 fps when i level off. when i make a turn, stutter disappear and i gain 20 fps back.

 

That's interesting isn't it ?

 

by the way i still don't the answer on why it goes this way

 

Maybe something linked with nvidia gforce xperience ?

 

its weird anyway

 

I wouldnt get hung up on it being vsync. Its not vsync causing the issue, well it is kind of, but the alternative is switching it off and thats likely to be far worse overall (your tolerance to uneven frame pacing may be different to mine. Mine is Zero. Like Worrazen says you are processing more stuff at low level and your system is struggling to render enough frames with the settings you are running at.

 

Assuming you have a 60 hz monitor it very much sounds like youre bouncing in and out of the 60/30 vsync cut most of the time. In a bank you see a 20 fps gain which indicates the vsync is cutting in and out many times a second becasue your are not able to produce the number of frames required (eg 60 for a 60hz monitor) consisently. You wont see the changes fluicutate that much as FPS counters average frames over a second.

 

When the load increases as you fly level (and you see more ground) you are unable to produce the floor limit of 60 fps at any time so Vsync cuts the frames to the next whole step (30) and keeps it there hence you see 30 on the counter. Which kinda makes sense since you see gound on both sides in level flight but less so when banking. Vsync is just doing what it does. Its not broken.

 

In a dogflight, presumably at higher level, you seem to still be only just about the 60 mark as it is occasionally dipping to 55 (again vsync is cutting from 60 to 30 several times over the second affecting the average). A stronger system/lower demand on the system would allow more headroom and keep vsync locked at a solid 60fps.

 

Perhaps have a look at your settings. Default terrain shadows affect fps significantly over flat and the low terrain textures can save some VRAM. Both come with a slight cost to the overall niceness of everything though. After that anything above 2X MSAA is likely too much and the other smoothing options are also likely to be too much as well.

 

Without knowing how you run DCS settings and your resolution this is of course a total stab in the dark. I run something not too dissimilar (6600K @4.5 and a 1080) and im on the limit at 1080P in 2D even with decent but unabitious graphic settings.

[mtpiperpilot]

I'm also having something similar happen, but the difference is banked, straight and level, it doesnt matter. I get stutters regardless. I've pretty much ruled out graphics settings - even with everything all the way to the left, it still happens, despite a crazy high frame rate. I have an older machine, but can still fly with medium/high settings and framerate locked at 30fps.

 

For me, it seems like the factors involved are MSAA - will amplify the stuttering to an unplayable degree. Vertical Sync doesnt seem to affect the stuttering frequency at all...on or off, it's about the same. The other factor that appears to reduce both GPU utilization and framerate, and increase stuttering, is going to full screen mode (using the checkbox in settings). Alt-Enter no longer appears to do anything at all except flicker the screen in 2.5.6. Meaning, you can hit the key command but it wont actually take you in/out of full screen. But, for me at least, unchecking the fullscreen option and running boarderless fullscreen also increases framerate, GPU utilization, and reduces stutters.

 

None of this was the case in 2.5.5. I had fluid gameplay, with few stutters, and could use Alt-Enter.

 

More info from my experience, here: https://forums.eagle.ru/showthread.php?t=263428&page=35