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[G-Sync Question] G-Sync Appears Choppy at Low Framerates

Discussion in 'Rivatuner Statistics Server (RTSS) Forum' started by EerieEgg, Apr 18, 2019.

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  1. EerieEgg

    EerieEgg Member Guru

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    Hi there guys,

    I recently acquired a G-Sync monitor and ran some tests with results I wanted to ask about.

    Of course generally I'll be running games at framerates high enough that this isn't noticeable, but I'm wondering if an unsmooth/choppy appearance is normal at low framerates for G-Sync or if it's a configuration issue on my end.

    The settings I have for my G-Sync monitor are as follows:

    -- Enabled for windows and fullscreen in Nvidia control panel settings
    -- V-Sync forced to ON globally in control panel, but set to OFF ingame. My understanding is this is needed for Nvidia's special G-Sync frametime compensation to work properly
    -- If it matters, max prerendered frames is set to minimum (1)

    For testing, I compared my old monitor capped at 30 fps (via Rivatuner) with Half-Refresh V-Sync forced in the control panel (double buffered) with my new monitor capped at 30 fps using G-Sync instead of the half-refresh v-sync.

    What I noticed is that the G-Sync test had noticeably less input lag and no tearing, but that it did not appear smooth at all -- the motion of the camera looked very choppy.

    On the other hand the half-refresh v-sync w/ 30 fps cap traditional double buffered v-sync method appeared very smooth, but had a noticeable increase in input latency.

    Is this just how G-Sync works, or do I have a setup issue of some kind?

    Notably, at high framerates, you can't really tell/perceive the choppiness.

    Thanks for your time!
     
  2. EerieEgg

    EerieEgg Member Guru

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    @RealNC Sorry to bother you about this, but I figured you may hold the answer if you get the chance to take a look. Thanks
     
  3. RealNC

    RealNC Ancient Guru

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    @StephenEnzor
    No, it's not normal. Is it a g-sync monitor though? Or a "g-sync compatible" freesync monitor? There could be a difference. G-sync monitors are guaranteed to have a smooth LFC down to 1FPS. Freesync monitors might not.

    Also, try vsync OFF. For 30FPS, you shouldn't need any frametime compensation.
     
    Last edited: Apr 28, 2019
  4. EerieEgg

    EerieEgg Member Guru

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    Thanks! Not certain what you mean by LFC, but my monitor is true G-sync. When using RTSS to cap, the choppiness is not present so I expect this was caused by the in-game limiter having bad framepacing or some such. I’ll give turning off Control panel vsync a shot then and see if that helps — having it ON is necessary for Gsync to function properly at higher FPS though I’d thought.
     

  5. RealNC

    RealNC Ancient Guru

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    It depends on the game and the frame limiter. With RTSS, you can usually have vsync OFF even at higher frame rates (of course only as long as your FPS cap is about 3FPS below max Hz.)

    Most of the time there are no negative effects when using vsync ON with g-sync and an FPS cap. But in some rare cases, vsync ON can cause some stutter in some games. So when that happens, you can disable vsync to see if it helps.
     
    Last edited: May 1, 2019
    EerieEgg and eGGroLLiO like this.
  6. EerieEgg

    EerieEgg Member Guru

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    @RealNC Thank you for your advice there, that's helpful! You say that with RTSS, you can have VSync off even at higher framerates -- I assume that is the case only if you are capping your fps to a 95% (or so) maintainable framerate though, right? So, if you cap with RT at 141, but the game only runs variable between 80-120 most of the time, I expect then you'd still need vsync set to ON for the frametime compensation feature, but if you were capping your fps to 70 or 80 where the frametime delivery is consistent then you could disable vsync in the control panel without issue.

    Am I understanding that correctly? Thank you for your time! What you said there is helpful.
     
  7. RealNC

    RealNC Ancient Guru

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    @StephenEnzor

    It depends on the game. Games are usually perfectly tear-free with vsync OFF when the FPS drops below the cap. Personally, out of all the games I ever played, I only encountered one that tears in this case: Prey 2017.
     

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