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Bobsk8

Be careful with the FFTF tweak.

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I probably should have worded it better.

 

Cheers, Rob.

But it's still true there's no need for this tweak when running unlimited FPS, correct?


Richard Åsberg

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But it's still true there's no need for this tweak when running unlimited FPS, correct?

 

Yes, that's correct.

 

Cheers, Rob.

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Yes, that's correct.

 

Cheers, Rob.

Got it, thanks Rob!


Richard Åsberg

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Yes, that's correct.

 

Truly sorry Rob, but it is absolutely NOT correct.

If FIBER_FRAME_TIME_FRACTION is set to 0.0 while using unlimited frames, the following will happen:

 

1. Autogen BUILDINGS do not get loaded (trees will be)

2. There will be minutes of gaps relatred to terrain loading (apart from the initial load)

 

So no, you were mistaken, as FFTF is also working when using unlimited frames.

 

Potroh

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So no, you were mistaken, as FFTF is also working when using unlimited frames.

 

No need for apology, correcting or challenging information in a polite manner is part of the process and good for all.

 

I was passing along information I got from LM.  

 

For my own testing with FFTF I saw no changes at all (I was looking at Time between frames data) with FFTF values from 0.01 to 0.99 when I was set Target to Unlimited.  The only time I saw significant changes in time between frames was with Target = locked frame that was higher than I could achieve consistently.  I must admit, I didn't test FFTF = 0.0 case ...

 

I just tested the FFTF = 0.0 and sure enough the Autogen buildings do not load and Terrain loading is slow.  However, all other values 0.01 to 0.99 show absolutely no difference on my setup when Unlimited + Vsync is set.

 

I'm not sure I'd say FFTF is working with unlimited just because the 0.0 case ... don't know enough about the code to determine that.

 

I do agree that FFTF = 0.0 is causing some evaluation even when set to unlimited which I didn't expect.  But for other cases I honestly don't see any value > 0 and < 1 making any difference to time between frames for Unlimited.

 

Are you see difference when using Unlimited + Vsync with FFTF values other than 0.0?

 

Cheers, Rob.

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Rob, as I mentioned earlier in the thread, 0.01 just gave me huge "blurries" on the terrain textures with unlimited set. I'll post a couple of comparison screenshots sometime soon to explain it better. It doesn't really make much difference when you're up at 30,000 feet but you can definitely see it at a lower altitude.

 

On reflection, this actually makes sense. This is not aimed at you Rob, just in general...

As you fly closer to a 'bubble' of terrain, the LOD improves and the textures are loaded at a higher resolution the closer you get. With FFTF set very low, the engine reduces the priority of this terrain texture loading. if you pause the sim and look at the terrain directly below the aircraft, you can actually see it loading the higher resolution textures as real time passes, although this can take upto a few minutes. I found it really jarring. (I think technically it has to do with Mipmapping, but it's all a little over my head! :))

 

Setting FFTF to 0.01 would definitely help on lower-end systems with low res textures etc. but if you're on a decent system using medium-high settings, there's hardly any difference in performance with anything other than 0.33. This is just my opinion by the way, it's what I saw on my own system.

 

I'll give it another go with the frame limiter set.

 

By the way, I find things like this funny. posted by NickN of 'Bible' fame...

 

 

bozos who claim FFTF=0 works are idiots..  that forces a .33 or default

http://www.simforums.com/forums/thanks-nick-for-your-bible_topic52380_page2.html

 

The moral of the story is, if you're tweaking and thinking 'nah, changing that value will never work' just *try it* and see for yourself. That's how come we now know about things like OPTIMIZE_PARTS


Neil Andrews.

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Rob, as I mentioned earlier in the thread, 0.01 just gave me huge "blurries" on the terrain textures with unlimited set.

 

Interesting, that does seem to indicate that FFTF is being used ALL the time regardless of Unlimited or Lock ... perhaps I need to revisit the information I got from LM ... maybe I misunderstood and my own testing is skewed based on my settings and CPU performance.

 

Certainly will add this to my P3D notes doc and maybe beg for clarification at the source.

 

Cheers, Rob.

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I was passing along information I got from LM.


Are you see difference when using Unlimited + Vsync with FFTF values other than 0.0?

 

No problem Rob, it happens and it's surely understandable - part of the game...

Some weeks ago (when I saw folks coming up with the 0.01 tweak) I also did some tests and on my high-end system, the results were as such:

1. I never use anything else but unlimited frames, as according to me (and in sync with some old Aces friends, who did that) the internal limiter is buggy and is a bad part of the original code. (One can easily see that it is not only limiting the upper part of the max value, but also lowers the average frame-rate considerably).
So sorry, I can't speak for either Vsync or t-buffer and the like...

2. Thus, using unlimited AND putting the FFTF value at 10.0 (well above the default into the skies) you can observe the terrain loading, autogen loading and also loading the higher or highest mipmaps of the terrain tiles MUCH faster and almost perfectly. BUT it also introduces constant and almost permanent stutters at the same time. (even one sec actual stops occasionally...)

3. At the other corner, lowering the value to 0.01 results better framerate and overall fluidity, but every terrain element gets loaded rather late. One will perhaps never see the original bitmap getting depicted (apart from highest mip-map of it).

4. So there IS a difference, but it seems to be very little between values 0.01 and any of the high integers. I also checked if the changes were gradual between the values, and they seem to be just that, although the visible differences truly need large fractional changes.

Potroh
 

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Rob, that's what I was trying to tell you previously. FFTF does work with unlimited.

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Rob, that's what I was trying to tell you previously. FFTF does work with unlimited.

 

Sure does Jay


Rich Sennett

               

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1. I never use anything else but unlimited frames, as according to me (and in sync with some old Aces friends, who did that) the internal limiter is buggy and is a bad part of the original code. (One can easily see that it is not only limiting the upper part of the max value, but also lowers the average frame-rate considerably).

Perhaps this needs explaining. Here's a quote I made in another discussion:

 

"When your fps is above 60, and your monitor is 60Hz, you only ever see 60 of those frames. This means that your time between frames is very short, and consistent. When your fps drops below 60, and you have Unlimited fps setting, the time between frames is determined by the time to draw each frame. You will notice the panning of Track IR, and also the panning of views, speeds up and slows down in time with the draw time, or image complexity.

 

If you have not studied the way panning works, do it now; set Unlimited and find a scenario that sits between 20 and 50 fps, say at an airport, and with an outside view pan and keep panning. The speed of rotation increases and decreases.

 

Now try fixing the fps below the worst fps seen with that scenario, and pan horizontally in the outside view, and keep panning.

 

Even though the updates are less, you notice two things; the time between frames is consistent so the panning rotation speed is consistent, and most importantly movement appears detached from the frame rate, as if in a separate process. This is designed in with FSX/P3D to improve the physics, and improve the handling of the aircraft, and response of the controls. To achieve this, the sim generates look ahead frames, and computes sim physics, and control throughput, based on a consistent time period. This results in a more accurate simulation and consistent aircraft handling.

 

The problem with fixed is that the look ahead frames eat into the maximum available fps, since it has to do work ahead of time. Remember the reserve of look ahead frames (usually 3) are used up keeping things smooth when the image complexity increases."


Steve Waite: Engineer at codelegend.com

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This is why I have always found texture loading better with fps locked and always smoother. You cannot run at full out and then not exspect stutter etc when the sim needs to load something and you have given it no head room at all.

 

30 fps Locked LOD 6.5 and with 0.01 =Job done, perfect texture loading and smooth. If you run unlimited and get stutter or poor textures loading you know why. :smile:

 

I did a flight from FT Toronto to FB KIAD I entered a total placket of cloud at FL32 ASN and cloud coverage set to max within P3D and only came out of it at FL 7000 and there was KIAD approach and area perfectly loaded smooth as silk.


David Murden  MSFS   Fenix A320  PMDG 737 • MG Honda Jet • 414 / TDS 750Xi •  FS-ATC Chatter • FlyingIron Spitfire & ME109G • MG Honda Jet 

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This explanation why locked FPS would be preferred over unlimited makes perfect sense giving the simulator be it FSX or P3D some headroom but in my case unlimited FPS has always given me the most smooth experience as well as the highest performance.

 

Can't explain why though, that's just the way it is over here and always been.


Richard Åsberg

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Good for you Richard.

 

Richard can I ask, do you use TrackIR?


David Murden  MSFS   Fenix A320  PMDG 737 • MG Honda Jet • 414 / TDS 750Xi •  FS-ATC Chatter • FlyingIron Spitfire & ME109G • MG Honda Jet 

 Fenix A320 Walkthrough PDF   Flightsim.to •

DCS  A10c II  F-16c  F/A-18c • F-14 • (Others in hanger) • Supercarrier  Terrains = • Nevada NTTR  Persian Gulf  Syria • Marianas • 

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Good for you Richard.

 

Richard can I ask, do you use TrackIR?

 

Yep, I do use TrackIR and was actaully going to add that to my comment since I think that might be why I prefer unlimited over limited FPS. I simply cannot achieve the same kind of smoothness moving my head with locked FPS.

 

However for anyone not using TrackIR locked FPS might very well be the way to go.


Richard Åsberg

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