Reducing Input Lag

Discussion in 'Technical & Support' started by Noel Hibbard, Jun 27, 2014.

  1. Noel Hibbard

    Noel Hibbard Registered

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    I personally found that rF2 runs the smoothest when you turn off VSync and then cap the frame rate slightly below your average frame rate with the "Max Framerate" option in the PLR file. If I enable any form of VSync, even adaptive vsync, I get inputlag. With VSync off and Max Framerate set I get zero input lag and a really smooth framerate. Although I do get some screen tearing which I am willing to deal with.

    What other combinations are people using?
     
  2. Ari Antero

    Ari Antero Registered

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    yes, you are right if you have single monitor.

    With my system(780 SLI triple screen) you must use VSync at 120 fps, if you don`t and fps drops only 5 fps you get stutters, micro stutters and input lag.
    If you use lower fps like 75 fps with HDR or off you have micro stutters, input lag and game looks horrible.

    Only setup I found witch gives smooth frame rate, no input lag is locked at 120 fps VSync on, no HDR, I am using SweetFX HDR not as good as rFactor2 HDR but I don`t think there is any better option for me.
     
  3. Noel Hibbard

    Noel Hibbard Registered

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    Have you ever tested with "Max Framerate" at all. Also the steady frame option. Dot recall the exact name of the option.
     
  4. Ari Antero

    Ari Antero Registered

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    Yes, at 60,75,100, 120 all gives me micro stutters, but it is known isue with SLI settings :(
     
  5. Spinelli

    Spinelli Banned

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    All forms of vsync add terrible input lag (vsync looks beautifully fluid though).

    Disable all/any forms of Vsync for minimal input lag.

    Setting "render ahead limit" (or whatever it's called) to "1" in your NVIDIA control panel may help as well (but may or may not reduce smoothness and/or fps).

    Also, shoot for 120 fps, with minimums no lower than 90 (except the start of the race which is understandable) EVEN IF YOU HAVE A 60 HZ monitor.

    Finally, there is the monitor itself which makes a huge difference. If you want minimum input lag then you really need to get a proper monitor that's designed for minimum internal processing and input lag, fastest pixel response times, highest refresh rate, etc. I would pretty much only choose 1, or 3 :) , of the following:

    Absolute lowest total input lag:
    24" - ASUS VG248QE
    24" - BenQ XL2411T / XL2411Z
    27" - BenQ XL2720Z

    The BenQ XL2420T and XL2420Z may have a tiny bit more input lag than their brothers listed above: the BenQ XL2411T and XL2411Z. Even if they do though, they are still ultra low.
     
    Last edited by a moderator: Jun 28, 2014
  6. Adrianstealth

    Adrianstealth Registered

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    agreed, racing sims and vsync is not a bad idea

    lower resolution and graphical settings for fps of 90 minimum ( ideally nicely over 100fps )
     
  7. Jamie Shorting

    Jamie Shorting Registered

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    does the 64exe affect input lag at all? I just got a sub 57second lap at LRP with the skip and default setup, which is a pb for me and I had to tell someone. lol. I was messing around with my pedals and increased throttle travel today as well so it could be that too. Anyway, thanks for listening.
     
  8. KeiKei

    KeiKei Registered

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    Well I'm using adaptive V-Sync @120 Hz combined with 2D LightBoost hack and input lag is really low. Couple of old threads with some good and still valid information about the topic:

    http://isiforums.net/f/showthread.p...ery-low-input-lag-(but-in-expense-of-details)
    http://isiforums.net/f/showthread.php/9888-Input-lag-measurements

    However I believe G-Sync will be the ultimate best option for both input lag and smoothness of rendering but haven't tested yet as there's no appropriate display available yet (27" G-sync with at least 120 Hz refresh rate). But there will be:

    http://www.blurbusters.com/gsync/list-of-gsync-monitors/
     
    Last edited by a moderator: Jun 28, 2014
  9. Denstjiro

    Denstjiro Registered

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    I used to cap and sync after allot of testing, it ran the smoothest this way.
    But then I accidently build660 and everything changed, now no capping, no sync, even smoother. (sync/capping in 660 was horrible)
     
  10. Spinelli

    Spinelli Banned

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    G-Sync adds just a touch of input lag actually.

    EDIT: Oops sorry, yes you're right, in terms of the best option for smoothness and input lag then G-Sync would be a billion times better than VSync. G-Sync only adds a very slight touch of input lag compared to no VSync at all, most people won't be able to tell though.


    I did tests of each VSync setting in rFactor 2, it was the good ol' test where you enable the on-screen steering wheel and hacksaw your wheel left and right very fast. All 3 VSync options, while having a different amount of input lag to eachother, had more input lag than none at all. Setting "render ahead limit" in the NVIDIA control panel to "1", if I recall correctly, did help the VSync options lower the input lag slightly, but even then they all still had more visible input lag than no vsync.
     
    Last edited by a moderator: Jun 28, 2014
  11. KeiKei

    KeiKei Registered

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    Yeah it will be great! Only drawback IMHO because ULMB (Ultra Light Motion Blur) cannot be used when G-Sync is in use. But I'm pretty confident I'll prefer G-Sync over low motion blur.
     
  12. Spinelli

    Spinelli Banned

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    Well G-Sync will basically look very fluid and tear free even when frames dip and stuff, but man, 2D lighboost / U.L.M.B. looks so amazingly fluid and life-like. I mean you theoretically need something like 750 Hz and 750 fps of non-stroboscopic (non-lighboost, non-ULMB, etc.) monitor gaming to match the fluidity and clarity that you get at 120 Hz / 120 fps of stroboscopic monitor gaming.

    G-Sync will always make it look smooth as if you always have V-Sync on, and the refresh rate of the monitor is always matched to the fps of the game, however even V-Sync at a matching 120 Hz / 120 fps gets completely blown away by lightboost / ULMB at just 100 Hz / 100 fps, let alone 120 Hz / 120 fps. However then you have to worry about/can notice framerate drops, tearing, etc.

    Do you want the consistent smooth image (fps-@-refresh-rate-while-using-vsync kind of smooth) and the tearing-free consistency of that image which G-Sync can provide, or the most amazing, fluid and life-like clear visual gaming experience possible with lightboost / ULMB while being susceptible to framerate drop stutters/un-smoothness, tearing, etc.??...

    I know, for me, choosing between stroboscopic and G-Sync would be a very difficult choice. I'd probably choose G-Sync for most games with inconsistent framerates like Battlefield 3, Battlefield 4, Watch Dogs, and such, but for games where I can keep a consistent framerate I would probably use 2D lightboost / ULMB. Once you get used to stroboscopic monitor gaming, it's so hard to go back to "regular" monitor gaming like G-Sync, V-Sync, etc. However the G-Sync would work absolutely beautifully for most new games that can't achieve a consistent and mostly locked-at framerate of 100 or 120 fps.

    My own personal choice is easy though, because once you use NVIDIA 3D vision (or any form of 3D gaming, but NVIDIA seems to do it best) then you can't go back to 2D gaming and therefore the question regarding stroboscopic vs G-Sync mode is irrelevant because 3D must use stroboscopic mode.
     
    Last edited by a moderator: Jun 29, 2014
  13. KeiKei

    KeiKei Registered

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    I know, going to be tough choice. But if I put 500+ euros to new display then I'm pretty confident I'll be using the only new feature in it which I don't have with my current gear! ;) :D

    Speaking about 3D I'll probably get the cheapest G-Sync 27" because my goal is in Oculus Rift. Should I already start preparing myself for it by using lower resolution? :p
     

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