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S_r_d_a_n  K_o_s_t_i_c

30FPS on 60Hz - usual stutters, can be improved?

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S_r_d_a_n  K_o_s_t_i_c

Smoothing. Kinda have to laugh and think of smoothies right now... lol.

Anyway, in the quest for better and better, I was searching of a way to "smoothen" out the pans and looking around the cockpit (and of course the flight itself and any kind of movement actually), not only for A320, but in general.

The problem arises when we run 30fps on 60Hz screen. In FSX this was overcome with the NI setting to half refresh rate. But that only works in the exclusive full screen, how FSX operates. P3D cannot use that, so we know that.

So there's a bit of testing I was doing lately. With P3Dv3HF3, I was (until now) running 30fps locked on my 60hz screen. Was never really happy.

Then I by trial and error tried 30,5fps lock in NI. That made the sim smoother, however introduced slower texture loading and input lag.

And then, just through the simple idea, I thought of additionally locking FPS inside the sim to 32fps and putting FIBER_FRAME_TIME_FRACTION=0.01 into prepar3d.cfg. That negated the max-fps fps-drop in P3D and made the texture loading better.

Activating VSYNC on + buffering in the sim solved the problem with the input lag.

In the end: everything smooth, sharp textures, max-fps is the same as unlocked sim. Way better than 30fps locked in the sim.

This setting is quite new on my machine, didn't have lots of time to test it out, but currently showing itself as promising.

Maybe someone who likes to experiment could try and report back?

Thanks

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Gianluca Balloni

Confirm! In this last weeks used frame limiter in inspector at 30.5, with fast vsync and 31 lock in sim, vsync+tb off in p3d. On 60hz monitor...this is the best solutions at moment for smooth sim! One question...other settings in your inspector?

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777cap

Thanks Kosta.. Going to try this out ASAP.

Do you think it's better enabling vsync in the sim or by enabling it in the inspector?

I have been using the 1/2 refresh rate+ adaptive vsync in the inspector.. Still haven't used the fiber frame time fraction tweak.

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S_r_d_a_n  K_o_s_t_i_c

 

 

 

 Confirm! In this last weeks used frame limiter in inspector at 30.5, with fast vsync and 31 lock in sim, vsync+tb off in p3d. On 60hz monitor...this is the best solutions at moment for smooth sim! One question...other settings in your inspector?

 

 

It is but exactly about the vsync+tb in p3d. Without that, I have a huge input lag. I researched about that, and it is the most suggested solution. Just google external frame rate limiter and input lag...

 

Do you think it's better enabling vsync in the sim or by enabling it in the inspector?

 

 

To my experience, there is no effect when using NI vsync, since we are using borderless windowed in P3D, and not exclusive full screen, like FSX.

 

 

 

 

 

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ai_ab

I've spent this week testing FFT, NI frame rate and other parameters since prepar3d.cfg I was using since HF1 resulted in long texture loading times.

The refresh rate of my display is 100Hz with GSYNC, HT is enabled. AM=85.

I also tested with HT off and without AM entries.

I have figured out that both FFTF=0.01 and the frame rate lock (both the one in P3D and in NI) were the cause of long texture loading times. I have removed FFTF entry and performed multiple testes with frame rate limiter setting it to ~25.4 FPS. I found that frame rate limiter does not affect texture loading times only if HT is ON and without AM entry. If HT is OFF then frame limiter resulted in long texture loading times.

I have about the same frame rate with HT OFF without AM and HT ON + AM=85. There might be a 1-2 FPS difference in favour of HT OFF (it is very hard to be sure whether this difference is due to HT OFF or it is the observation error). However, the stutters become very noticeable stutters with HT OFF, while the image is quite smooth with HT ON.

Here is the description of FFTF:

Benefits
Reducing the value can improve FPS.

Detriments
Reducing the value too much might prevent higher resolution textures (blurriness) from loading.

 

So it is hard to say why the texture loading has improved with FFT=0.01

I should add that with HT ON + AM=85 I get 5-10 FPS increase during the flight.

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S_r_d_a_n  K_o_s_t_i_c

Interesting observations. However, HT is for me a no go. I pursue the highest max frame rate, as this is in my opinion the most important part. It can mean that in some situations I get 28 instead of 31 fps, and that causes huge stuttering and lag.


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ai_ab

With the double frame rate limiter it looks like there are no major issues with texture loading.

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S_r_d_a_n  K_o_s_t_i_c


With the double frame rate limiter it looks like there are no major issues with texture loading.



Maybe. I'm afraid there might be issues when the system cannot cope with the set frame rate, being limited by the CPU, not GPU.


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ai_ab

Yep, clearly using the double frame rate limiter solves the texture loading issue compared to the single frame rate limiter in my case.

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Gianluca Balloni
4 hours ago, Kosta said:

Interesting observations. However, HT is for me a no go. I pursue the highest max frame rate, as this is in my opinion the most important part. It can mean that in some situations I get 28 instead of 31 fps, and that causes huge stuttering and lag.


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...yes...same consideration...When fps low to 30 (also 28 for example), stutters are gone.

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Gianluca Balloni

...and on my i7 7700k@5,0ghz, i'm use ht off without am, only fiber at 0.01 in .cfg. I don't now if use ht on with am85 see much difference in fps and smooth. Test it in next filghts!

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Konstantin

Hi Kosta,

Thank you so much for the tip!  I have a 60 Hz screen, and I also struggled with getting P3D v3 to run smoothly. When I limited the frame rate to 30 fps internally, the sim was mostly fluid, but every dozen seconds or so I noticed some "jerking" that emerged for a split second. This was especially noticeable during taxi (when you focus on taxiway elements) and during flight when you look out of the window. This was not because the computer system couldn't keep up with 30 fps (with unlimited frames, I would see 40-50 fps), but because of apparent synchronization issues. Turning on VSync and Triple Buffering didn't help. I have to say that I mostly use unlimited frames especially for tubeliner flights between busy airports to achieve the highest possible FPS. For VFR flights at high graphics settings, not limiting the FPS brings my GPU to 100%, and the stutters get bad even though the displayed FPS are relatively high. This is where I limit my FPS to 30.

I have applied your "trick", and it works like a charm!  On my recent test flight above Switzerland with ORBX Vector + OpenLC, I have experienced a smoothness of unprecedented consistency. Everything is fluid, and no more jerking!  I will apply the trick for my next tubeliner flight. Not only does it help achieve smoothness, but it also reduces the GPU temperature during cruise flight (without limiting fps, you would see very high frames, but the video card runs at close to 100%).

So again, thank you very much for the best tip on smoothness that I have ever seen. :)

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Jose Francisco Ibañez M.

4K 30Hz capable monitor. That was the best purchase i ever made for flight sim. Smoooth as butter.

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S_r_d_a_n  K_o_s_t_i_c

Sadly, with v4 I had no success at achieving what I had with v3. For some reason that jerkiness remains with v4. I didn't go as far as to install windows fresh, just for the sake of testing, but I did install v3 and checked it against v4. v3 = smooth, v4 = not.

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NilsUnger
57 minutes ago, Jose Francisco Ibañez M. said:

4K 30Hz capable monitor. That was the best purchase i ever made for flight sim. Smoooth as butter.

I think this - or a gsync monitor - is the most sensible way to go to get rid of this everlasting nuisance. 

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S_r_d_a_n  K_o_s_t_i_c

Well, my monitor does 30hz, however I hate the mouse lag.


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