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FIBER_FRAME_TIME_FRACTION

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FIBER_FRAME_TIME_FRACTION=0.01  In Main Section of Prepar3d.cfg

 

In the past I had 10fps in NY USA. Now, depending upon the view, I get a very acceptable level of performance. All scenery sliders to the right. Limited AI/traffic to 10. MSAA at 2. At 8 =10fps again. 

 

LOW END System/rig/PC

 

nVidia GTX550 1gb memory, Intel 2550K over clocked to 4.3ghz, 8GB of memory/RAM

 

Aircraft P3D/Carenado Bonanza

 

Similar results at the ORBX Redding, CA airport and desert area. I have had some nice FPS in the past but the next day the same area gave me poor results. The tweak is the only change I have made tp P3DV2.4. My clouds are at High Detail 70 miles. Cloud shadows on. but limited to 10,000 meters. First 4 check boxes are set on bothe sides. Water at low. 

 

I have no idea of the underlying processes affected.

 

 

kdGwa.jpg

 

 

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I think that is the speed at rendering scenery. I might be wrong, which is weird because it should have slowed the speed of loading down.

 

One of the wonders of FSX I guess. It should give you better performance and I guess if you only fly low and slow should not give you an issue with the blurries. I would try something a little faster and report back too to see if you get blurries flying over dense areas like that wonderful shot you posted.

 

I might try this myself for my Airbus, as I dont check the scenery out as much at 30k.

 

Thanks for sharing and looking forward to hearing back!

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I have no idea of the underlying processes affected.

 

Hi Dick:

 

The original reference to "FIBER_FRAME_TIME_FRACTION" ...by ACES' Phil Taylor:

 

http://blogs.msdn.com/b/ptaylor/archive/2007/05/11/tweak-of-the-week.aspx

 

 

 

...and some more  links:

 

https://www.google.com/search?q=FSAX+phil+taylor+FIBER_FRAME_TIME_FRACTION&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=nts#rls=org.mozilla:en-US:official&channel=nts&q=FSX+phil+taylor+FIBER_FRAME_TIME_FRACTION

 

 

Hope this helps ! :smile:

 

GaryGB

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Hi Dick - it does indeed work. In the past with FSX, the downside with using such a low FFTF was almost instant blurries; with the P3D multi-threaded engine, you can have you cake and eat it too :Party:

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In case anyone is interested in what a "fiber" is:

 

http://en.wikipedia.org/wiki/Fiber_(computer_science)


Hi Dick - it does indeed work. In the past with FSX, the downside with using such a low FFTF was almost instant blurries; with the P3D multi-threaded engine, you can have you cake and eat it too :Party:

I have never had FFTF have any impact on FSX or P3d before. But before today,  I have never set this variable below 0.15 in either sim. When I set it to 0.01, in P3d, it does indeed give a few more FPS (maybe 10-15%) and no blurries at all.

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I was building up to starting a thread FFTF=0.01 and I am glad it has been started. In my opinion the only .cfg tweak that was worthy of the advent of P3D V2.X was FFTF=0.10. Despite my earlier misinterpretation of FFTF I know get it. So I can say that lower you set it the higher your FPS but the more likely it is that you will see blurries. Given that the the default is 33% it is not surprise that reducing it to zero gives a 50% FPS increase.

However you will see blurries in P3D V2 if you set FFTF=0, However and this is a surprise to me at 0.01 you may not see blurries at all. I am very surprised by this. I thought I was doing well to be able to get the benefits of FFTF=0.10 without blurries but in fact I am getting much better performance with FFTF=0.01 and still without blurries.

 

I will try to quantify this over the next few days but I can tell you that my early impressions are very promising.

I don't think zero works but I will try 0.001 and see what happens:-)

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I am surprised I am only hearing about this now

 

so what happened to 0.001?

 

must have melted your PC?

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Tested a few FFTF values. I think 0.01 is indeed the best. No blurry's higher frame rate.

0.001 got huge FPS increase but terrible bluries and missing autogen. Graph made by sampling FPS at 30sec intervals on Recorded flight.

 

Strangely enough the Ground textures in the FSDreamTeam where not effected by blurry with a value of 0.001 while the surrounding ORBX ground Textures where a blurry mess. Probably priority in scenery library.

 

0.01 is the winner:-)

FFTFanalysis.png

 

Here is the flight that was used:

https://drive.google.com/file/d/0B4aX5Q3-OT6kQ0tsTktaTmZtZlk/view?usp=sharing

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Nice tests! Just curious, did you test FFTF=0.05 or FFTF=0.005?

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Thanks Dave, really interesting result. Two questions:

 

- Which fps limit did you set? According to all I read FFTF does only work with limited fps.

 

- If so, how does this compare (blurry/fps wise) with an unlimited fps Setting (that's what I use at present)?

 

Kind regards, Michael

 

 

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Nice tests! Just curious, did you test FFTF=0.05 or FFTF=0.005?

You are correct its a typo on the graph it should read 0.005 i.e. half as much time as 0.01 and virtually no difference that I could see.

 

According to all I read FFTF does only work with limited fps.

Don't think that's accurate. My FPS is set to unlimited in P3D V2.4 Display setting.

Didn't see any blurries until I tried 0.001 and then lots. And as I said no additional benefit to 0.005 but I do think I noticed during the start of the playback on that one an area of ground texture come into focus but just once.

 

I should make a stutters and FPS comparison adjusting the FFTF value with frames locked to 30 and Vsync on.

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Thanks Dave. There was, e.g., a thread on the LM forum not long ago with just that general opinion (although no one from the LM staff contributed, as far as I recall). The more I read the more confused I get. Same goes for all those AA settings.

 

Anyway, thanks for the thorough test, very well done.

 

Best regards, Michael

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From my experience with "aiming for high FPS" I can only say that a solid balance of parameters will give the most stable results.

IMO the consequence of high FPS settings "here" is creating a bottleneck "there" resulting in stutters "at the end of the flagpole" (as we say in Germany).

Choosing parameters that will result in more than 40 FPS is for sure a bench mark test for high end machines, but here the question might not be if stutters will come, but when they will occur.

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So no blurries at 0.01? Interesting. I will also check again.

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I will upload the 0.10 and the 0.01 video's to youtube

and post the links here.

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I will upload the 0.10 and the 0.01 video's to youtube

and post the links here.

 

Dave, your 0.001 result was very very interesting and gave me an idea.

 

First with unlimited frames, I tried the FSXMark11 and got these results:

 

FFTF = 0.01

 Min  Max  Avg 22 37 33.475

No blurries. 

 

FFTF = 0.001

 Min  Max  Avg 34 49 42.058

Plenty of blurries, in-fact no autogen.

 

 

 

Next I set frame limit to 42 and got this:

 

FFTF = 0.001

 Min  Max  Avg 30 41 37.025

No blurries!!

 

So if you got this, by setting a limit close to the average FPS at 0.001 ( obtained with no frame limit), here 42, I am able to eliminate the blurries and also gain FPS (33 to 37). This frame limit I believe given enough time to the sim to autogen/texture.

 

Notice that we also increased the minimum frame from 22 to 30. Maybe this helps with stutters too.

 

Can you also try this? Preferably with FSXMark and record avg time with Fraps.

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I can CONFIRM that FFTF = .01 is a KEEPER!

 

And bear in mind that I am running MegaSceneryEarth photoreal textures, where you really need something like FFTF = .40 to reduce blurries.

 

With .01, my textures are sharp as with .40 but with better performance! Definitely a keeper, guys!

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Dave, your 0.001 result was very very interesting and gave me an idea.

 

First with unlimited frames, I tried the FSXMark11 and got these results:

 

FFTF = 0.01

 Min  Max  Avg 22 37 33.475

No blurries. 

 

FFTF = 0.001

 Min  Max  Avg 34 49 42.058

Plenty of blurries, in-fact no autogen.

 

 

 

Next I set frame limit to 42 and got this:

 

FFTF = 0.001

 Min  Max  Avg 30 41 37.025

No blurries!!

 

So if you got this, by setting a limit close to the average FPS at 0.001 ( obtained with no frame limit), here 42, I am able to eliminate the blurries and also gain FPS (33 to 37). This frame limit I believe given enough time to the sim to autogen/texture.

 

Notice that we also increased the minimum frame from 22 to 30. Maybe this helps with stutters too.

 

Can you also try this? Preferably with FSXMark and record avg time with Fraps.

 

Duke, I can also attest to this! When I tried .001 earlier today, I was getting HORRIBLE blurries. After reading your post and locking my FPS to 40, the terrain is once again razor sharp! No blurries whatsoever and FPS were outstanding!

 

I did a quick lap on the AS A318 around Taxi2Gate's KMCO with MSE Florida. With my settings (no HDR, no cloud shadows), I was averaging low 20s while on short final.

 

After doing the .001 tweak, I was averaging upper 30s! I even went ahead and enabled DSR/cloud shadows and I was still averaging mid 30s on short final.

 

Thumbs up in my book! The terrain is super sharp but with the added FPS, it just feels so smooth and natural.

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So if you got this, by setting a limit close to the average FPS at 0.001 ( obtained with no frame limit), here 42, I am able to eliminate the blurries and also gain FPS (33 to 37). This frame limit I believe given enough time to the sim to autogen/texture.

Sounds reasonable to keep the FPS below the maximum achived. This should prevent the textures to "stall".

On the other hand, being at the limit might introduce stutters. As I said before: there has to be a headroom for higher demand intervals...

 

I will give 0.001 an unlimited and limited try but in my case with external limitation through nvidia inspector 1/3 refresh rate as I prefer unlimited internally...

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With the 0.001 setting and limited FPS I get a small amount of blurries. At 0.01 and unlimited, everything looks great. Now I'm trying to decide whether DSR makes things look any better.

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Wondering how this "tweak" affects other stuff such as tesselation at various settings. This ain't your daddy's FSX...

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So no blurries at 0.01? Interesting. I will also check again.

 

I tried 0.01 and true, there were insignificant blurries, ... well fed texture threads though resulted in an OOM on final

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Extremely low FFTF like 0.001 or 0.01 mean that you share only 1/1000 (or 1/100 respectively) of CPU per frame time for fiber actions. If your CPU is very fast these time fragments will be sufficient. But the slower the CPU is (or gets due to other tasks) the more one will see blurries and/or missing autogen.

I am still running my old PC system and here texture/autogen degradation is a problem.

 

In the end this test shows that it makes sense to have a very high potential PC, BUT at the same time config tweaking still seems to be necessary (or advantageous) to achieve better results (frame rates) in P3Dv2. Actually I hoped that "tweaking thing" would become a thing of the past and capable GPUs could make our day...

 

As I said before: the right frame rate number is less a question of quantity than a question of sustainability. And with highly demanding scenarios (scenery+weather) and complex A/Cs a stable framerate beyond 35 is an utopia.

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true, after all, are we flight simmers or frame simmers

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Looks like that FFTF=0.01 or FFTF=0.001+Locked FPS is shaping up to be the best performance tweak discovered so far for P3D!

 

 

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