Can't get freesync to work :-(

Discussion in 'Videocards - AMD Radeon' started by SpajdrEX, May 25, 2019.

  1. Truder

    Truder Ancient Guru

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    Double buffered does lock framerate, triple buffered doesn't on the other hand however using vsync, when framerate is below optimal increases latency as more blank frames are inserted.

    I would suggest reading this so you understand how vsync works. https://www.anandtech.com/show/2794/2

    The point is, you're eliminating the benefits of freesync by using vsync as you have frames inserted to compensate - output framerate with vsync is actually a buffered framerate (hence input lag). It is quite complex though to understand but simple answer is don't mix vsync with freesync - you're overriding the benefits of freesync.

    As for Enhanced Sync, this is so you can exceed framerates capable of your refreshrate - yes it only uses the most recent frame available on the monitors cycle and you may even get some tearing but it's a compromise feature, particularly where games have little framerate controls (or frame capping utilities offer little solutions - FRTC is awful imo).

    Also for reference I use freesync - I have a 144hz panel with 40-144hz range.

    Edit: There are some situations where freesync will work with vsync though and this is when game performance goes above or below vsync tolerances (and assuming this is within your monitors freesync tolerances) but frankly, only real situation I'd consider enabling vsync is if it's just incredibly difficult to control/limit fps
     
    Last edited: May 30, 2019
  2. Richard Nutman

    Richard Nutman Master Guru

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    All games use double buffering as a minimum if they care about performance, as you can't render the next frame until the driver has finished with the last one.
    Whether Enhanced sync, Vsync or Freesync is enabled makes no difference to this.

    Triple buffering has nothing to do with locked frame rates as such, it allows games to render the next frame when the last frame is still waiting for Vsync. It was a performance improvement.
    Triple buffering is completely redundant with enhanced sync or high refresh rate monitors.

    "by using Vsync as you have frames inserted to compensate" What?! I think you're talking about Low Framerate Compensation ? They are not blank frames, the driver just repeats the last rendered frame so the monitor doesn't have to drop too low in refresh rate. There is no increased lag as the game is running at the bottom end of the Freesync range anyway.

    You don't get tearing with enhanced sync if you're above the monitor refresh rate, that's the whole point of it. On a non Freesync monitor you get tearing when you drop below the monitor rate as the driver then disables Vsync to prevent stutter.

    If your game is at 200fps and your Freesync monitor max is 144hz, then yes you may want to turn on Enhanced sync if you really care about the last bit of input lag. But it's worth pointing out in this situation that Freesync isn't really active under this situation anyway. Your monitor will just be running at constant 144hz.

    Freesync only engages when you drop below monitor refresh rate, and it's worth pointing out then that Enhanced sync is no longer active.

    Mate, I don't need to read up on Vsync. I'm a programmer that spent 16 years working in games. :)
     
  3. Richard Nutman

    Richard Nutman Master Guru

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    It's worth pointing out that Freesync monitors still have lots of bugs though, so may cause weirdness.
    My Gigabyte Aorus (which is GSync certified) completely failed to use Freesync just now in Doom and other games simply by having a Raspberry Pi plugged into one of the HDMI ports!
     
  4. Truder

    Truder Ancient Guru

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    Well yeah that's the point of enhanced sync.... So I'm glad you understand that then...

    Right, so you do know what vsync is and you know what a blank frame is, repeated frame from the buffer. I believe you're mixing up my explanation of buffering with LFRC (maybe my explanation is crap fair enough) but it is there in that article, the frame is being held that extra cycle so considered a blank frame.

    Eitherway I provided materials that explain vsync. Yes there are circumstances where you can still use vsync, for example if whatever you're playing will always maintain a fixed frame rate and not suffer any drops in which case freesync is unnecessary, but unlike enhanced sync, you don't necessarily get the latest frame possible on each cycle, only the frame currently in the buffer.

    Edit: Just saw that you posted this after

    I've had something similar happen to me before but rather having stuttering occurring in everything thanks to having a second monitor plugged in but that was driver issues some time ago, not a freesync issue itself (as in the monitor) so I'd pen your issue there to drivers not behaving as they should.

    Edit again: Actually I've misunderstood this one haven't I? Nothing to do with multi-monitors You're using two devices on one monitor? (I was wondering why or how you'd plug the pi into a gpu hdmi port... had it the wrong way round :D) I've heard about this before actually where having a second devices plugged into a monitor disables features (some high refreshrate monitors for example wont allow you to use high refreshrates if there are other devices connected). Do you have PIP (picture in picture, if your monitor has that feature) enabled (not necessarily active). Or it might be that your monitor wont use freesync if it has other signals being processed.
     
    Last edited: May 30, 2019

  5. Richard Nutman

    Richard Nutman Master Guru

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    Yeah my PC is on display port, and a Pi on HDMI input. Yeah actually now I retest it, it wouldn't allow above 60hz.. annoying.
    I think it does have PIP but I've not tested it or enabled it.

    I tried putting a frame rate limiter on and disabling Vsync in Doom, and could instantly see tearing and stuttering even with variable frame rates.

    This monitor definitely works best with Freesync + Vsync.
     
  6. Chastity

    Chastity Ancient Guru

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    @Only Intruder

    You're not exactly right on how VSync + FreeSync (VRR) works together.

    When both are enabled, VSync is fully enabled ONLY when at max framerate, or when the frames are falling below the VRR range. When within the VRR range, VRR takes over, and VSync is supplying frame compensation timing to remove tearing. And that's it. You still get the benefits of VRR's low input latency.

    This is why it's been recommended that when using VSync + FreeSync that you cap the framerate to maxfps-3, or whatever number below max that works on your system. (I use maxfps-1 with my 1070) This keeps the framerate in the VRR range, preventing VSync to fully enable, which causes hitching when it switches to and from VRR, and prevents VSync's full latency. Thus, you have low latency, no tearing, and smooth gaming at any point within VRR.
     
  7. Truder

    Truder Ancient Guru

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    Isn't this only if a game uses triple buffered vsync because I've found when games uses double buffered (sometimes games only have the option "vsync on/off" too), if frame rate dips below 144, vsync will force the frame rate to drop down to 48 or worse 36 (you'd think it'd go to 72fps first) thus overriding freesync so this is why I'll often avoid using vsync (instead using enhanced sync in drivers). (Or can just be weird interaction with certain games or drivers being sh*t).
     
  8. Chastity

    Chastity Ancient Guru

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    No, this works if double or triple buffered. (Anything using DWM is triple buffered, aka windowed borderless fullscreen) If you are having VSync issues futzing with the fps, then disable VSync in-game, and force it on in the game profile in NVCP.

    @Only Intruder
     
  9. Truder

    Truder Ancient Guru

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    AMD GPU here... Remember, our vsync options are limited/rather strict in drivers, only able to force triple buffering for OpenGL.
    [​IMG]
    We're at the game's mercy

    Enhanced sync was a very welcome addition when it was introduced given the very poor vsync options we have in drivers
     
  10. Chastity

    Chastity Ancient Guru

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    Still the same principle. You can use Enh Sync or Always On, both accomplish the same goal. You can also use FTRC and Chill to find your performance sweet spot, and to cap fps. RTSS is also an alternative.

    Disabling fullscreen optimizations may give your game a better environment for exclusive fullscreen mode. (Good for older games)
     

  11. Truder

    Truder Ancient Guru

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    Aside from Enhanced Sync, the vsync options in drivers don't actually work properly (they only work for legacy titles under for example DX9) as AMD follows DirectX specifications as opposed to Nvidia who optimise everything which means it's up to the gamecode and/or windows to manage vsync.

    You might remember this thread where it was discussed in quite a lot of detail. https://forums.guru3d.com/threads/o...-change-what-about-essential-features.402851/

    FRTC and Chill are subpar options in my experience - Chill being... awkward on the Fury at least it's not very graceful and it is always limiting framerate if you're using devices other than keyboard/mouse and Xinput controllers (i.e. using a HOTAS, chill ignores those inputs) and FRTC with it's brute force frame rate cap (unlike RTSS which does it CPU side).
     
  12. Undying

    Undying Ancient Guru

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    I actually used enhanced sync before i got a freesync monitor. With the combination of the two i've noticed some strange framerate skipping and stuttering, its not working as it should.

    Disabling vsync and enhacned sync while using frtc+freesync works best.
     
  13. OnnA

    OnnA Ancient Guru

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    For problematic Games im using RTSS -> FRT is OFF and Chill is set 65-70FPS.
    Working OK.

    Rage 2 = Ok
    BFV = Only in .cfg (FRT OFF)
    HoMM VII = OK but smoother is w/RTSS
    DOOM = Ok
    UBI Big Games = RTSS only w/Chill if used.
    Forza MS7 & H3 = OK

    All in all it depends on Game & API
     
  14. Undying

    Undying Ancient Guru

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    I didnt yet encounter problematic game @OnnA and i dont use chill at all.

    Tested Dishonored outsider, DMC5, Evil within 2, Rage 2, Star citizen and League of legends.

    72hz monitor, vsync off- frtc 70fps +freesync, its smooth and am yet to see the tearing.
     
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  15. SpajdrEX

    SpajdrEX Ancient Guru

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    Undying : try Assassin Creed Origins, if you get smooth scrolling while rotating camera :)
     

  16. Undying

    Undying Ancient Guru

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    Dont have the game sorry.
     

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