LFC out of sync (Freesync issue)

Discussion in 'Videocards - AMD Radeon Drivers Section' started by Synoxia, Jun 21, 2019.

  1. Fox2232

    Fox2232 Ancient Guru

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    Feel free to continue here. Your case is indeed very unusual. I did try this demo. And setting 30fps in it resulted in LFC giving out 90Hz while 60 would be OK.
    But demo itself behaves in very weird way. even limiting to 20fps utilizes my GPU to 100%.
    But moving slider to 500fps while I have RTSS global limit to 225fps results in 70~80% load. Sometimes utilization goes down to 5~10% while fps is maintained.
     
  2. Synoxia

    Synoxia Member Guru

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    Try a game. Witcher 3 at 30fps RTSS for example gives from 58 to 61hz now with clean driver install + HPET stock which is not correct. Correct fluctuations is from the video of the other user.
    Which GPU are you using? Win10 version?
     
  3. Fox2232

    Fox2232 Ancient Guru

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    Win 10 18362.175, RX-580 8GB.

    One of things to consider is that not every monitor (or firmware version) shows refresh rate in real time accurately. Mine is damn bad at it. But at least it does not try to show decimal spaces.
    OSD of my screen fluctuates much more, but actual images are displayed on expected rate.
    (Redownloading W3 from steam. Will take a while. But I'll try some other games in meanwhile.)

    Edit: I think I did replicate your issue in Dead Island. limiting to 30fps results in same 90Hz refresh.
    But occasionally Hz goes much above 100. And game is not displaying smooth 30fps, it is stuttery as hell while displaying 30 fps.
    40 fps results in 80Hz and occasional jump above 100 while it is much smoother. I think that issue comes from tripling frame when it is not needed as game makes new frame in meanwhile.
    20fps results in 80Hz with occasional jump above 100 as above. But I think I see like 5 different frames per second only.
    10 fps does not even trigger LFC and screen sits in 240Hz mode. Feels like 2 fps. But in reality there are more, they are grouped in short time intervals and then there is huge timing hole.

    I think it is pacing issue at very low fps. But it may be that game engine is not able to cope with being limited that much. (since RTSS believes that it gets frames at requested rate.)

    Yes, 240fps recording confirmed that there is some frame grouping. Unfortunately, Radeon Settings is unable to limit fps in Dead Island and that means I can't make comparison.
    (Will look for other game.)
     
    Last edited: Jun 26, 2019
  4. Synoxia

    Synoxia Member Guru

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    That guy in the other thread has your same GPU and my same monitor.
    He doesn't have weird fluctuations as we do.
    As we speak i was trying to use Vsync 50hz + RTSS instead of freesync. Smooth as butter.
    Where freesynced 50fps 50-51-52hz is also tearfree but not as smooth.
    I have to chose between input lag or less smooth motion when i have paid for freesync technology.
    If that isn't pathetic this will be: i can't even make that choice because the game i am playing (BatmanAK) has awful antialiasing, so i have to use VSR 4k resolution to get rid of it.
    Guess what? Using VSR forces 120hz refresh rate and ofcourse AMD doesn't support half refresh vsync, so no 60fps + half vsync option even if i decrease resolution/settings.
    I wanna die.
    All i wanted was a perfect butter smooth game.
    You should report this issue aswell so AMD can fix.

    EDIT: 50fps with freesync enabled results in 90-100hz OSD and ofcourse random microstutter.
    LFC is kicking in even outside it's range? WTF? My monitor is 48-144 range so 49hz and 50hz should work...
    gg amd
     
    Last edited: Jun 26, 2019

  5. Fox2232

    Fox2232 Ancient Guru

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    Killing Floor 2 behaves much better. 20fps limit still results in 80Hz, but fluctuation is very close to 80Hz and does not have those spikes above 100 while I can see stable rate of displaying frames. Where I believe I see 20fps.

    I think that AMD is guilty as charged with LFC tripling refresh when not needed, or quadrupling... I think that frametime (shown fps) issue comes from games not being able to handle themselves at low fps. Some engines probably tick at fixed rate and when fps is too high or low, they freak out.
    (Like bethesda's on high fps.)
     
    Last edited: Jun 26, 2019
  6. Synoxia

    Synoxia Member Guru

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    Then thell me why the other user has no issue? Did you even see his video? His fluctuations are 0.4hz max, while mine is mostly +1 +4 and even +20hz. I am monitoring frametimes with afterburner and a 100ms (minimum you can set) refresh period.
    When i am playing at 50fps frametimes are basically stuck on 20ms while everything (gpu usage etc) fluctuates.
    I know what software reports isn't 100% close to what happens in the game but i think we can fairly say it's 90% close atleast?
    Because those refreshrate aren't even close to 90% in following the actual FPS!
     
  7. Fox2232

    Fox2232 Ancient Guru

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    There is chance that it has something to do with newer driver. Given video is from January.

    Anyway, I disabled FS and went to retest Dead Island on 20fps. It had exactly same frame grouping stutter as with FS. Therefore in that case it is really bad engine.
    I think that main question for you is, does game stutter? I think that overblown LFC is not causing damage. It just does refresh when it is not needed.

    I can actually think of one reason why to do it that way. Monitors have different motion/response compensation techniques and most of screens end up behaving differently at different refresh rates. Therefore keeping actual refresh rate around some value can reduce blur from response time.

    And side note for time difference between given video and now. I am at that build where MS implemented that Variable refresh rate "Force" feature which can be enabled/disabled.
    Maybe some change which integrated this to windows have unforeseen side effect.
     
  8. Synoxia

    Synoxia Member Guru

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    Video is from january and today i still have the same issue.
    That user mentioned said he has retested now and he have no issue.
     
  9. Fox2232

    Fox2232 Ancient Guru

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    What about port on graphics card? Are you using DP or HDMI?
    FS was 1st supported via DP and AMD added HDMI support later.
     
  10. Synoxia

    Synoxia Member Guru

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    DP 1.2 included xg2401 cable.
     

  11. nikobellic

    nikobellic Member

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    Yah, in my case with newer driver I had to reduce it to 56-60, but on 18.6.1 or older driver it was working just fine with the default "LCD Reduced" blanking value. Don't know what the hell AMD did in the driver since then.
     
  12. Synoxia

    Synoxia Member Guru

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    @Fox2232 idk how i did it but for some time my freesync started to work correctly, check this and tell me that freesync is supposed to fluctuate. Game has perfect framepacing? Freesync has perfect hz.

    unfortunately after this it broke again for some reason... might investigate, maybe it's something regarding chill.

    EDIT: ok seems like RTSS is actually breaking freesync... wtf... if you want working freesync at capped refresh you have to tinker with FRTC and rtss... because FRTC has broken frametimes but doesn't break freesync while RTSS has even frametimes but breaks freesync.

    EDIT2: Anything that it isn't FRTC breaks Freesync.
    Chill minimum = broken freesync
    In-game cap? = broken freesync

    Seriously amd...
     
    Last edited: Jun 28, 2019

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