Matt Piotrowski

Does 1/2 refresh rate work?

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Posted (edited)

I have a 144hz monitor and I was thinking of using 60hz and 1/2 refresh rate with sim locked at 30 FPS? Does this work? Or should I just lock my sim at 30 FPS?

Edited by Matt Piotrowski

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Posted (edited)

For me it seems smoother. 60hz locked to 30fps is smoother than a variable refresh above 30 FPS. If you can’t hold a constant 30 though then it will get a little choppy! 

Edited by djbully

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5 minutes ago, djbully said:

For me it seems smoother. 60hz locked to 30fps is smoother than a variable refresh above 30 FPS. If you can’t hold a constant 30 though then it will get a little choppy! 

I’ve heard from some people that 1/2 refresh rate doesn’t work with p3d. Is that true?

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29 minutes ago, Matt Piotrowski said:

I’ve heard from some people that 1/2 refresh rate doesn’t work with p3d. Is that true?

I believe it does not work since P3D is not true "full screen". It needs full screen to work. I have set my monitor to 30 Hz and have activated vsynch in P3D settings.

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1 minute ago, Peter Webber said:

I believe it does not work since P3D is not true "full screen". It needs full screen to work. I have set my monitor to 30 Hz and have activated vsynch in P3D settings.

My monitor doesn’t go to 30hz.

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Also when I use 1/2 refresh rate and 30 FPS on 60hz do I use adaptive vsync and triple buffering in inspector?

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I used just normal vsync, I don’t notice any input lag with it. It could just be placebo effect. But seems smoother locked at 30 I don’t use triple buffer. 

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1/2 refresh rate works extremly well with my setup. I don't use NVI, I set half refresh rate in Nvidia Control Panel. The settings in P3D are:

VSync off

Triple Buffering unchecked

Unlimited

 

This eliminated most of the stutters I experienced when panning in outside view.

Be aware that you need to be able to render 30+ frames most of the time for this to be effective.

 

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2 hours ago, Matt Piotrowski said:

I have a 144hz monitor and I was thinking of using 60hz and 1/2 refresh rate with sim locked at 30 FPS? Does this work? Or should I just lock my sim at 30 FPS?

It certainly does not work as it is supposed to work ie limit your P3D frame rate to half your monitor's refresh rate. As you see above there are claims that it does work in the sense of making P3D run better. Whether this is system dependent or just placebo, who knows. Just try it and see if there is any difference. My experience is that both the half refresh rate and adaptive Vsync settings do nothing.

With a 144 Hz monitor you might be better experimenting with "quarter refresh rate" in NI and 36 fps in P3D (144/4=36.)
Can you set your monitor to 36Hz refresh rate?

gb.

 

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Posted (edited)

It doesn’t work like it did in FSX as P3D uses a ‘false’ full screen so even when the window is maximised it’s actually running in windowed mode. FSX used a proper full screen but LM disabled this on grounds that it could be buggy. 

I fixed this by buying a monitor that could run at 30hz and this forces the frames to 30. 30fps is usually achievable most of the time with good hardware and sensible settings. One day we may be able to get 60fps as the lower limit, so there would be no need for the half refresh tweak.

With triple buffer on and frames to unlimited then as long as you can maintain 30fps the sim is very smooth. The smoothness comes from the fact that each frame is drawn within one refresh cycle of your monitor. 

Edited by Airline2Sim
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Posted (edited)

Maybe your display does do 30hz. But you should contact the manufacturers customer support to verify before you force it. Just because the display doesn't report it doesn't mean it won't do it. Make sure you contact the manufacturer first though by email and get a confirmation from them that its OK before you do it.

You would use NCP to create a custom resolution with a 30hz refresh rate.

My disclaimer is that if you monitor has a heart attack and dies its not my fault because I told you to contact the manufacturer to confirm it will work first.

Typically this warning is given when you want to apply a refresh rate above the displays maximum refresh rate. But you know!

I can't see there being a problem with sending a 30hz signal to a display that reports 60hz compatibility.

After you have confirmed by email with the display's manufacturer that sending a 30hz signal to the display will not damage it, you would tune you setting to deliver about 35fps with Frame Rate set to unlimited and Vsync off. Once you've done that turn on Vsync and you should see a smooth, constant and stutter free 30fps.

Running at unlimited frames is though on rendering sharp textures and autogen so your CPU will need to be up to the task otherwise you might see blurries and outrun autogen.😀

Edited by Avidean

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Are there any 1080p monitors that can run at both 60hz and 30hz?

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I have a 4K g-sync monitor that is native 60Hz.   I have been noticing some unwanted  autogen and lights popping and some blurries so I’ve been thinking about tweaking my monitor to help.  What would be the best route to adjust to help...????

 

A) turn off G-sync and limit frames at 30 in P3D

B) leave g-sync on and change monitor refresh to 30 Hz

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12 hours ago, Matt Piotrowski said:

I have a 144hz monitor and I was thinking of using 60hz and 1/2 refresh rate with sim locked at 30 FPS? Does this work? Or should I just lock my sim at 30 FPS?

Hi Matt,

I too have a 144Hz monitor. I achieve very smooth results by reducing the monitor frequency to 120Hz (which is more than plenty for general usage) and locking P3D at 30fps (no VSync or TB). The rationale behind this is that a P3D frame will coincide with every 4th refresh of the monitor. Really quite surprised this technique isn’t adopted more widely by those of us who don’t have 30Hz capable monitors. However, as with other methods, it does rely on sufficient overhead being available, when needed, to maintain 30fps in P3D. That’s where switching custom Display profiles to suit particular flight situations comes into play.

Edit: G-Sync is NOT used for P3D as I have found results to be very inconsistent.

Regards,

Mike

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Posted (edited)

There are plenty of HDTV that support 1080p at 30hz. That's what I used before moving to VR (Samsung Odyssey+)

The problem with setting your Frame Rate to 30fps is that the P3D Frame Rate Limited has a huge overhead. I have always found that if I tune the sim to run above 30fps with Vsync off and Frame rate set to Unlimited, that with the exact same display setting, setting the Frame rate to 30 nearly always delivers an actual FPS well below 30. That's with FTFF=0.33 which is default. If you set FFTF to zero you'll get your 30fps but you will also get blurry textures and in some cases no autogen. I suppose with Dynamic fibertime or what ever it's called this can be addresses but that's the reason I never found setting the Frame rate to 30 in P3D display setting worked well.

Edited by Avidean

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Yes it’s a well known phenomenon that locking your frame rate actually makes performance worse than leaving it unlimited. If I set my monitor back to 60hz and lock the frames within the simulator to 30, the smoothness of the half refresh tweak is gone. 

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When I have my frames at unlimited and 144hz my game isn't smooth. When I use half refresh rate and 60hz with fps capped at 30 fps my game feels smoother.

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10 minutes ago, Airline2Sim said:

Yes it’s a well known phenomenon that locking your frame rate actually makes performance worse than leaving it unlimited. If I set my monitor back to 60hz and lock the frames within the simulator to 30, the smoothness of the half refresh tweak is gone.  

Hi, Been experimenting this this and have found the following.

1), yes locking the frame rate in P3D typically doesn't actually get you the frame rate you've set. That said I experimented with increasing the value of

  • [Display]
  • TEXTURE_BANDWIDTH_MULT=

The P3D default is 30, FSX-SE is 160, so I went to 160 and then incremented by 100 till I saw no appreciable changes, 760 was the result and now when I set 30 fps in the P3D slider. 30 fps is what I get.

Would proably depend on an individual machine and the silicon lottery but worth a go and it's easy to experiment with.

The advantage I see of it all is the frame rate is much more stable, and doesn't jump all over the place so much as when v-sync and unlimited frames is on.

2), To get the NVidia half refresh rate working I needed to disable Aero (I run Windows7) for which I wrote a small toggle script, so the 1/2 refresh tweak does work, although 30 Hz and v-sync is better but if I didn't have a 30 Hz monitor myself I'd use the 1/2 refresh tweak.

3), Even with 30 Hz, v-sync and unlimited framerate set a lot of spare overhead is needed as if the framerate drops under 30 v-sync drops off and a sudden and distacting "frame rate jump" occurs. (this is where the frame rate slider in P3D can help).

 

For those interested a 1080p monitor that can support a custom 30Hz value is the Dell MultiSync MHL IPS monitor (U2417H - can sync down to 23 Hz) .

Cheers

 

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I thought I would just add my experience of setting a locked frame rate.

I have a Freesync monitor set at 144Hz refresh rate, which uses Nvidia G-Sync by way of the latest Nvidia drivers. I have frame rate set as unlimited in Prepar3D v4.4, but lock the frame rate to 30fps using Riva Tuner Statistics server (RTSS). Provided that you set the frame rate in RTSS before you run P3D, the frame rate is indeed locked in P3D itself (although set as unlimited) and there are no penalties associated with such frame rate locking: i.e. if without frame rate locking 40-50 fps was usually achieved, the frame rate is solid at about 30fps with frame rate locking through RTSS and not say 20-25fps or less if you had frame rate locked at 30fps from within P3D itself. I also find that it may be necessary to set VSync to ON within Nvidia Control Panel, which seems to be a recommendation by AMD for the use of Freesync with their monitors, to eliminate some minor stuttering.

In this way, my own experience is one of very smooth performance indeed, with a marked reduction in stutters and also better control of what might have otherwise been a fairly widely-varying frame rate. That is not to say that anyone else will experience the same in so doing, but spreading the knowledge may help some.

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2 minutes ago, LecLightning56 said:

I thought I would just add my experience of setting a locked frame rate.

I have a Freesync monitor set at 144Hz refresh rate, which uses Nvidia G-Sync by way of the latest Nvidia drivers. I have frame rate set as unlimited in Prepar3D v4.4, but lock the frame rate to 30fps using Riva Tuner Statistics server (RTSS). Provided that you set the frame rate in RTSS before you run P3D, the frame rate is indeed locked in P3D itself (although set as unlimited) and there are no penalties associated with such frame rate locking: i.e. if without frame rate locking 40-50 fps was usually achieved, the frame rate is solid at about 30fps with frame rate locking through RTSS and not say 20-25fps or less if you had frame rate locked at 30fps from within P3D itself. I also find that it may be necessary to set VSync to ON within Nvidia Control Panel, which seems to be a recommendation by AMD for the use of Freesync with their monitors, to eliminate some minor stuttering.

In this way, my own experience is one of very smooth performance indeed, with a marked reduction in stutters and also better control of what might have otherwise been a fairly widely-varying frame rate. That is not to say that anyone else will experience the same in so doing, but spreading the knowledge may help some.

Do you have gsync on?

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1 minute ago, Matt Piotrowski said:

Do you have gsync on?

Matt, yes my apologies, I do indeed have G-Sync switched on.

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Just now, LecLightning56 said:

Matt, yes my apologies, I do indeed have G-Sync switched on.

Thank you, I will try this.

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11 minutes ago, Matt Piotrowski said:

Thank you, I will try this.

One further thing, Matt, is that you should keep Riva Tuner Statistics Server running once having set the frame rate. In order to set frame rate in RTSS, enter e.g. 30 in the appropriate box which will flash, press enter to select it and then minimize RTSS (do not close it down). RTSS runs in the background and you will find that the frame rate stays locked in P3D (although of course set as unlimited in P3D itself).

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You can also limit the frame rate in NVI.

That is what I do..  In P3D the setting is on Unlimited.

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If I use 1/2 refresh rate and 30fps limit in NVI do I use standard or adaptive tear control and do I use triple buffering in NVI?

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