G-sync stutter unless I limit frame-rate

Discussion in 'Videocards - NVIDIA GeForce' started by daninthemix, Sep 4, 2017.

  1. daninthemix

    daninthemix Member

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    I notice a minor but regular, reproducible stutter when running with G-sync + V-sync in most games (when frame-rate is at a constant 60fps). If I use Nvidia Inspector to limit the frame-rate to 58fps, the stutter is gone and the experience is as butter-smooth as I'd hoped when I bought into G-sync.

    But why? Why doesn't it remain smooth when switching over to v-sync mode?
     
  2. Agent-A01

    Agent-A01 Ancient Guru

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    You want to limit fps below refresh rate otherwise vsync will activate on.

    Use RTSS to limit fps to 58/59 fps.

    If you want to learn more about gsync go to blurbusters gsync 101 overview.
     
  3. ScoobyDooby

    ScoobyDooby Ancient Guru

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    Maybe I'm wrong here, but I thought you should be turning off V-Sync if you're using G-Sync. I have all V-Sync set to off in every game I play.. where I find I get stutter is when I use Fullscreen vs Borderless Window.. in many cases the latter plays perfectly where Fullscreen will be jittery more times than not.
     
  4. daninthemix

    daninthemix Member

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    Has to be NV Inspector as I'm not an admin (so can't launch RTSS). However, NV Inspector at 59fps is completely smooth (because it's keeping me in G-sync, I guess) and I'm not noticing any additional input lag (versus the V-sync that I was in before).

    Really my post was just asking WHY V-sync isn't smooth on a G-sync monitor? As in, my previous monitor WAS smooth as long as I stayed locked at 60fps, but since I switched to a G-sync monitor, there's minor stutter in every single game if I'm in V-sync.
     

  5. daninthemix

    daninthemix Member

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    This is really maddening. I've done further tests, on a section of game where i can reproduce the stutters:

    G-sync OFF + V-sync ON - SMOOTH
    G-sync ON + V-sync ON - STUTTER
    G-sync ON + V-sync ON + Frame Rate Cap - SMOOTH

    Why doesnt' this make any sense.
     
  6. fantaskarsef

    fantaskarsef Ancient Guru

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    It depends on your performance too. I have to say, until last weekend I was using my Gsync screen without any vsync activated. I haven't really had issues getting over the 144Hz in most games, but trying it out like Agent A01 and others advised really made a difference.
    It worked pretty well tbh, but going for Gsync + Vsync + frame rate cap (142fps for my screen) does really look smoother and better.
     
  7. cryohellinc

    cryohellinc Master Guru

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    Point of Gsync is low latency and smooth experience without impact on performance.
    Gsync works below your screens refresh rate. Vsync kicks in only after that range is exceeded.

    In my case on 100hz screen I use : gsync on for fullscreen and windowed + 98fps cap + Fast Sync.

    https://www.blurbusters.com/gsync/gsync101-input-lag/

    Read the whole article if you want to improve, otherwise do what ever you want.
     
  8. RealNC

    RealNC Maha Guru

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    If you can't use RTSS, you can instead try Dxtory. Also, make sure to cap to 58FPS, not 59. Tests have shown that 1FPS below refresh is not enough. You need at least 2.
     
  9. Netherwind

    Netherwind Ancient Guru

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    What about 144Hz screens, should those users cap to, let's say 140Hz?
     
  10. cryohellinc

    cryohellinc Master Guru

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    142 fps, always has to be 2fps below screen refresh rate. :)
     

  11. Netherwind

    Netherwind Ancient Guru

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    Great! :) But then my stuttering in ME:Andromeda must be tied to something else.
     
  12. riot83

    riot83 Active Member

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    Have you guys experimented with FastSync and G-Sync? Thats what I usually use. V-sync off in games

    Edit: From blurbusters: Do note, even at its most optimal, Fast Sync introduces uneven frame pacing, which can manifest as recurring microstutter.


    Well I'll be damned.
     
    Last edited: Sep 12, 2017
  13. PhantomGamers

    PhantomGamers Active Member

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    Just wanted to chime in here and point out that while 2 fps under your refresh rate is usually fine, the blurbusters article now recommends you to cap it 3 fps below.
     
  14. undorich

    undorich New Member

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    i hope it helps !!

    also have a look here

     
    Last edited: Sep 13, 2017
  15. yasamoka

    yasamoka Ancient Guru

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    Fast Sync allows your GPU to render at framerates above your refresh rate (e.g. 180FPS @ 144Hz) while still aligning the frames to your monitor's refresh (eliminating tearing). This would mean that out of 180 complete frames, only 144 complete frames are displayed each second. Hence, 36 frames are dropped each second.

    Those frames contain visual information that is based on the game's animation time - that is, animation that is intermediate to frames that were displayed, and now, due to dropping those frames, is missing. Thus, what you get is uneven frame pacing, especially since frames are not dropped in a regular pattern.

    However, if you had locked a framerate that was a perfect multiple of your refresh rate (which you will find is unfeasible given how framerate limiters cannot be perfectly accurate), where that multiple is "n", then for each n frames, you would drop n-1 frames and only get the last displayed. This would provide perfect frame pacing and decrease input latency considerably, given that the latest frames are always rendered and shown closest to the monitor's refresh interval, and you do not get old frames shown (those are now discarded).
     
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  16. Hammie

    Hammie Master Guru

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    All you really need is vsync if those other technologies are giving you lag and what not. gl
     
  17. Shadowdane

    Shadowdane Maha Guru

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    What your describing is inherit to uncapped fps in general.. if your fps is completely uncapped it will try to render the frame as soon as possible. So you'll get variation in your fps from second to second. That's just the nature of variable framerate unfortunately. Also running uncapped can hit your CPU a lot harder if you have a bottleneck there. Seen a few instances of people trying to hit ~100-144hz on a 1080Ti and a i5-2500K. Yes that CPU is a workhorse but it's a pretty big bottleneck now on these faster GPUs.

    Personally for G-Sync I ALWAYS set a fps cap to keep the fps smooth at the desired fps target! This provides the most consistent performance. It depends on the game and what fps I can actually hit but I usually cap my fps to 60, 90, 120 or 140fps. I keep my refresh rate at 144hz so i never hit the limit of GSync.
     

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