Lower Latency Option regardless of API?

Discussion in 'Videocards - AMD Radeon Drivers Section' started by Eastcoasthandle, Sep 19, 2020.

  1. Eastcoasthandle

    Eastcoasthandle Ancient Guru

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    I watched Battle(non)sense vidoeo explaining Reflex:



    The gist is that the added latency that traditional low latency technique used by them still allows the CPU to run ahead of the GPU piling up work in the rendering queue for the gpu to process. Even though you are GPU bound. Thus creating a backlog...

    Capping the frame rates in game to 60FPS creates a CPU bound situation that prevents any work in rendering queue which goes straight to the the GPU. Thus bypassing the rendering queue. The GPU is just rendering what the CPU prepared without the need for it getting piled up in the rendering queue.

    The issue is that this has to be implemented in game. However, if setting Main3D to 0/1 (I was told that 0 only reverts back to 3). Or capping the framerates to 60 does the same thing is there an easy way to also achieve this Flex on AMD GPUs?
     
    Last edited: Sep 20, 2020
  2. JonasBeckman

    JonasBeckman Ancient Guru

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    There's anti-lag and chill but you balance GPU and CPU bound with input lag and latency from what little I know, there's also SpecialK and I think MSI Afterburner for attempting to trim latency but it requires some configuring but it can have some very effective results depending on the game and game engine. :)

    Just normalizing frame time variance so it's at 33 (30 FPS) 16 (60 FPS) 8 (90 FPS?) and so on instead of fluctuating plus utilization of Windows 8+ and flip model presentation along with Windows 10+ and flip discard mode.
    Not all game engines take well to it though but the frame rate limiting functionality along with flip model support and low latency mode can make a really nice difference though direct implementation from the developers might have a edge though obviously that implementation as a game specific thing also a limitation.

    You also need the hardware or reducing the settings to keep framerate stable for how these other methods work.
     
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  3. aufkrawall2

    aufkrawall2 Master Guru

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    I've tested it in Fortnite on a 1660S and indeed it does lower input lag significantly, also with DX12 (unlike A-L / ULL, which don't work for 12 and Vulkan). I suppose it's some Nvidia binary lib black magic, it also requires a recent Nvidia driver. So I don't think we'll have this for Radeons, unless AMD releases their own counter part.
     
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  4. Eastcoasthandle

    Eastcoasthandle Ancient Guru

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    Well, I hope AMD responds to it.
     

  5. janos666

    janos666 Master Guru

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    It would be nice to see a comparison between AMD Alti-Lag and nV Reflex because the former outperforms LMM Ultra. (One would need to tweak the clock speeds and find some vendor-neutrally optimized game, so that both AMD and nV cards can run at closely the same framerate while being fully GPU-bound... or normalize the latency to the avergae framerate, etc.)
    Still, Anti-Lag is a driver switch (although probably limited to DirectX<=11 ???) and Reflex is an SDK, so the latter will be utilized a lot less often... unless Microsoft decides to help putting and end to this and offer a standardised version of Reflex in DirectX/WDDM (something like a "true Game Mode").
     
  6. aufkrawall2

    aufkrawall2 Master Guru

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    Did you see the video above? Latency in Overwatch is ~exactly the same with ULL ultra and Anti-Lag. I have tried both in all kinds of DX11 games and I have no reason to think that A-L would be superior in any way. Actually, the opposite is the case, as A-L often causes additional stuttering, whereas ULL ultra reduces it.

    If game developers really wanted to, they probably could simply reduce latency by themselves (for decades?). Gears 5 feels extremely direct and the frame time graph looks like CPU and GPU queue are very closely synced, just like in-game fps limiters or Reflex do.
     
  7. janos666

    janos666 Master Guru

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    Oh, LOL, I actually haven't! I mean, I jumped too quick too far to get the full graphs asap and missed those useful graphs in between. :)
     
  8. someonelikeyou

    someonelikeyou Active Member

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    It needs to be implemented in each game by the developer so it's dead on arrival
     
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  9. Eastcoasthandle

    Eastcoasthandle Ancient Guru

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    Watch at 6:50. He's using Reflex which was updated in MW to use (have to turn it on from the Graphics section of the game).
    From the looks of it the feature isn't mature, not working.

    Looks like the grass isn't necessarily greener on the other side after all.
    As you watch @7:14 take notice of the grates on the ground changing shape/color too. Looks like LOD being reduced. I wonder if that's the secret sauce to Reflex?
     
  10. aufkrawall2

    aufkrawall2 Master Guru

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    I suppose he reduced visual fidelity to get those high fps, it shouldn't be a result of less prerender. Though that feature would be more helpful with lower fps anyway.
    Availability of this feature is a valid point, I personally don't care much about such hyped MP shooters with a short life span anyway. Instead, I'd much rather would want it in e.g. Cyberpunk.
     

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