RTSS frame limiter delay measured

Discussion in 'MSI AfterBurner Application Development Forum' started by n2k3, Jan 20, 2017.

  1. n2k3

    n2k3 Member

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    A YouTube channel called Battle(non)sense, which is ran by a guy named Chris, measured the Button to Pixel (input lag) when using a G-Sync (or Free Sync) monitor in combination with the frame limiter feature of RTSS.

    It's explained in this video: https://www.youtube.com/watch?v=rs0PYCpBJjc
    where RTSS is looked at 3:52 in the video (but it is recommended to watch the full video).

    It seems that the feature in RTSS is better implemented than the similar Nvidia Inspector feature named Frame Rate Limiter.
    This basically means when a video game doesn't allow you to limit the frame rate in-game, you should set it in RTSS, as it will always have less delay than with V-Sync enabled.

    I'm wondering as to how that was achieved, and if it would be possible to reduce the delay even further, similar to when the game itself allows frame limiting?
    [Edit: it seems tests done in the G-Sync 101 post at blurbusters forum, show a way smaller delay introduced when using RTSS frame limiter.]

    Thanks :)
     
    Last edited: Jan 22, 2017
  2. BUDA20

    BUDA20 Member

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    I saw this using different limiters, in some games even a bad vsync implementation (like in Syndicate or Heroes & Generals) is fixed by using RTSS to a equal limit to the screen refresh (in addition to vsync)

    But for people who play in fullscreen with no vsync and no gsync, using nvidia inspector and frame limiter v2 will give you no tearing and no input lag.

    So RTSS has better timing, nvidia inspector has better sync to the monitor refresh, RTSS seems to be oblivious of the monitor refresh.

    *you will see a bit of tearing if the fps drop, but is still better that adaptive vsync
     
  3. X7007

    X7007 Ancient Guru

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    So you say using RTSS limiter when using VSYNC

    and when not using NVCP or In-Game Vsync to use Frame Limit Nvidia Inspector v2 ?

    Which is better to use as main rule, NVCP Vsync ON or In-Game Vsync ?

    For example no matter what I do with the game Ori and the blind forest , it always laggy like the frame Time is crazy , as long the Vsync in-game is disabled it's laggy, if I enabled it, the game is perfectly fine. So sometimes the in-game is a must and sometimes not, what do we do if we don't see an instant change ? and it causes randomly issues.
     
  4. RealNC

    RealNC Ancient Guru

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    This post is old and wasn't updated. For an up to date guide, use this: https://forums.guru3d.com/threads/the-truth-about-pre-rendering-0.365860/page-12#post-5380262

    Old post below...

    Inpsector has more input lag than RTSS.
    (This is an old post. The nvidia limiter is now pretty much as good as RTSS.)

    The best way to cap with vsync on is to cap to 0.006FPS lower than refresh using RTSS. You detect you refresh here:

    vsynctester.com

    And then configure RTSS to 0.006FPS below that. You need to edit the profile file and put this in it:

    Code:
    [Framerate]
    Limit=59934
    LimitDenominator=1000
    This is for 59.934FPS if your refresh rate is 59.94Hz. "LimitDenominator" determines the amount of decimals. So 1000 is the most useful one.

    This will give you the lowest input lag possible when using vsync.

    If you're not using vsync, then enabling the Inspector limiter will automatically enable adaptive vsync, which will give you the same input lag as vsync. So the nvidia limiter doesn't make much sense.
     
    Last edited: Sep 17, 2021 at 1:39 AM
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  5. X7007

    X7007 Ancient Guru

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    Which file do I need to edit ? I'm trying to edit the Global file in profiles but it says access denied when trying to save.

    ha, I will need to do one by one profile..

    EDIT : still doesn't let me
     
  6. RealNC

    RealNC Ancient Guru

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    That's just a Windows thing. I install RTSS in C:\Games and I can edit all files there. You can run Notepad as administrator though, then load the file.

    Coupled with setting "maximum pre-rendered frames" to 1 in the nvidia panel, you can get very little vsync lag when capping like this using RTSS.
     
    Last edited: Apr 9, 2017
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  7. X7007

    X7007 Ancient Guru

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    Right, needed to run as admin.
     
  8. BlindBison

    BlindBison Master Guru

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    How did you come to the value of -0.006FPS? Is it just a trial and error approximation? Would -0.01 due just as well or be worse? Or is it a trade off between more frequent stutter when it misses the v-sync window (since the framerate is very slightly lower than true refresh) and lower input lag? Thanks
     
  9. RealNC

    RealNC Ancient Guru

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    Yep.

    I recommend -0.01 anyway these days. No reason to make it as close as possible.

    Although why do you need this? You've got g-sync, AFAIK.
     
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  10. BlindBison

    BlindBison Master Guru

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    I do have G-Sync, but I have a traditional v-sync laptop I use from time to time :) Thanks for explaining, I appreciate it.
     

  11. RealNC

    RealNC Ancient Guru

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    Last edited: Sep 17, 2021 at 2:55 AM

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