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Claude Troncy

Relation between texture loading and external limiter ?

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Bonjour,

 

My PC... 4790K OC4.7ghz 780GTX W7 EIZO(60hz)

I am interested to have advices about the relation between external limiter and texture loading.

 

- When using external limiter (30FPS) (I tried 4 different ones), I can stop microstutters in turn and when panning.... But the textures are displayed with delay, and it looks like if they popup just in front of the plane.

 

- When not using the external limiter, I do not have the texture loading problem, they are displayed before, at a long distance in front of the plane, and the popup is imperceptible..

 

-When using internal limiter, no problem the texture are displayed correctly... But the overhead produced by the internal limiter makes my FPS dropped, and I am under 30FPS (using NGX) and again stutters are here.

 

I know some experts on this forum who certainly have an idea of what could explain the relation between the speed of texture loadind and external limiter.

 

Thanks in advance

Cheers

Claude 

 

 

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What happens if you use a higher cutoff instead of those 30FPS? For example 33, 36 or even 45FPS? Might be simply that the P3D engine changes priority of when using resources to load the ground textures depending on whether you set a framelimit or unlimited. And the external framelimiter then interferes with this "logic" leading to blurries.

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Hi AnkH,

Thanks for your answer, I think you are right.

 

Using a higher cutoff like 60FPS supress the behavior of slow loading texture.

That mean that on my config the external limiter slows the process of rendering terrain.

 

I searched how an external limiter works, and in FSX (I think it is the same in P3D) it slows down the main thread by putting it in sleep mode. That look strange to me but that could explain why some processes in charge of rendering terrain and related to the main thread are delayed. In fact when the textures are displayed(with delay) the plane is at a short distance of them and they seems to popup.

 

So I have to choose texture popup or stutters :smile:

May be i will try to post on the LM forum to see if someone of their team has another explanation.

Cheers

Claude

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Try using an Affinity Mask setting of "85" along with an increased TEXTURE_BANDWITH_MULT of "1800" along with no any other tweak, that should basically eliminate stuttering. In my case, as soon as I either add any FIBER_FRAME_TIME_FRACTION or any other tweak or another Affinity Mask entry, I get stutters instantly. I know that most systems react slightly different, but maybe it is worth trying.

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Hi AnkH

 

I already had the AM set to 85. This is the only tweak in my cfg file.

I tried TEXTURE_BANDWITH_MULT  with a value of 1800, but no change in stutters. The only thing that works for me to get rid of microstutters, is the external limiter, with the disadventage of the delayed texture loading problem.

 

Merci

Claude

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True, I also have this in my NVI profile, sorry for missing this one out.

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Salut Massimo,

 

 


Already tried this (you never know)?

Yes, it was set to 1 in NI.

 

A question... are you using a fps limiter ?

 

When I look to your config, the only difference with mine is mainly the GPU.

What i do not clearly understand is the negative effect on texture loading when an external limiter is used.

Cheers

Claude

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Claude,

 

I'm going with FPS unlimited in P3D (no external limiter) and VSync off as recommended for a Gsync monitor, and hence Gsync on in NCP.

No clue for your texture loading problem.

 

For the stutters: check the post! The author's talking about Nvidia Control Panel, not NVI.

 

Cheers,

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So if I look at the GPU usage....

- With external limiter 30 FPS, internal unlimited --- No stutters, and sim very fluid ---- GPU is about 55% -- texture displayed with delay .

 

- With no external limiter, internal limiter 33FPS --- microstutters - GPU is about 55% --- texture       displayed with no delay.

 

- With no external limiter, internal unlimited --- microstutters - GPU 98% --- texture displayed with no delay

 

More strange.

- With external limiter set to 30FPS, internal to 33FPS ---- No stutters - GPU 55% ---- Texture displayed with no delay.

So to have both limiters seems the solution except that with the 737NGX, the internal limiter ask to many cpu to make it's job, and the FPS is below 30FPS... And stutters.

 

Claude

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So if I look at the GPU usage....

- With external limiter 30 FPS, internal unlimited --- No stutters, and sim very fluid ---- GPU is about 55% -- texture displayed with delay .

 

- With no external limiter, internal limiter 33FPS --- microstutters - GPU is about 55% --- texture       displayed with no delay.

 

- With no external limiter, internal unlimited --- microstutters - GPU 98% --- texture displayed with no delay

 

More strange.

- With external limiter set to 30FPS, internal to 33FPS ---- No stutters - GPU 55% ---- Texture displayed with no delay.

 

So to have both limiters seems the solution except that with the 737NGX, the internal limiter ask to many cpu to make it's job, and the FPS is below 30FPS... And stutters.

 

Claude

 

I think you're ready to hit the real science here:

 

http://www.avsim.com/topic/477057-a-frame-time-analysis-of-p3d-v3-effects-of-cpu-affinity-frame-lock-and-ht/?p=3315905

 

This forum is an invaluable source of infos, thanks to everyone's contribution and willing to share.

Hope you'll find your sweet spot pretty soon, and enjoy your sim (I do!).

 

Happy flying,

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I've always got on better using the internal lock (at 30fps) over an unlimited rate and using an external limiter. The downside is you lose some performance, but as long as your budget is generally higher than your lock everything should be fine. I've always found external limiter allow more fluctuation, and a less smooth experience.

 

BTW I'm pretty sure the max range of TEXTURE_BANDWITH_MULT is 400 and putting it out of range will either defualt it back to that, or maybe its min value of 10.

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The downside is you lose some performance

Yes you are right the intermal limiter loose performance in FPS, but not in the process of rendering texture in the distance.

The problem with the external limiter, is that it put the main thread in a sleep mode to maintain the FPS. Unfortunately the time passed in the sleep is not use for rendering the texture, so that generates delay in the texture display.... that's what I understand in the Beau Hollis response on the LM forum.

Cheers

Claude

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