Which Graphics Settings affect CPU performance and which affect the GPU?

Discussion in 'General Hardware' started by BlindBison, Oct 26, 2019.

  1. BlindBison

    BlindBison Master Guru

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    Hi there guys,

    I'm trying to work out which graphics settings most impact the CPU since in my case I appear to most often be CPU limited (since I play with a 1080 Ti @1440p).

    My aim is to eliminate stutter and historically I've done this by capping the framerate (I despise discernible stutter I think even more than input lag though we all hate that too ofc).

    I recently read a comment on one of BattleNonsense's videos where the user claimed that stutter is caused by the CPU being "tapped out" while you can have a variable refresh rate without any stutter so long as you're limited by the GPU and not the CPU.

    I have no way to verify whether or not that's true, so I figured that I would ask about it here -- if that's so, then it seems like being GPU limited is much more preferable to being CPU limited (though my understanding is that if the GPU is totally maxed out at 99/100% you'll get some additional input lag at least in some games so perhaps that's not perfectly ideal either).

    In any case, from what i've read online:

    1) Texture Quality -- this is usually VRAM dependent and therefore unrelated to CPU or GPU performance (as I currently understand it at least -- correct me if I'm wrong and this has some other effect on the CPU for example -- isn't the CPU responsible for streaming data in and out of VRAM?).

    2) Object Quality -- from what I've seen online, this is more CPU dependent than GPU, but that's just hearsay -- I don't actually know myself.

    3) Phsyics -- CPU dependant from what I've read

    4) Draw Distance / Object Fade / etc -- from what i've read this is CPU dependent -- iirc Digital Foundry mentioned lowering this as a way to reduce drawcalls and relax the strain on your CPU, but it's possible that I misunderstood them here.

    5) AntiAliasing / Resolution / texture filtering -- GPU is my understanding for these.

    6) Maximum number of visible characters (NPCs or other players) -- for MMOs or in multiplayer games when many players are visible OR in games with a lot of NPCs on screen at once. My guess is that this is CPU dependent, but I'm not positive that's the case.

    7) Particle or Effects quality -- I've got no clue on this one.

    8) Reflections -- not sure

    9) Shadows -- people often cite this as one of the first things to lower from what I've seen online, but I'm not sure if that'll help out the CPU at all. Is this GPU or CPU dependent? Or, a bit of both perhaps? Are all of these settings "a bit of both" for that matter?

    Anyway, beyond these settings, I'm not sure and I wanted to verify that my understanding was correct for those settings in any case. Are there any other CPU dependent settings that I should consider? Is my understanding for the above settings correct?

    Historically my approach has been to avoid "Ultra" settings and cap the framerate to what is consistently achievable to improve framepacing and mitigate stutter -- but it's possible that I'm leaving a lot of performance on the table if I only need to lower CPU straining settings for example.

    Anyway, thank you for your help and time, I really appreciate it.

    EDIT: From what i've read as well, especially in Open World style games, "hitching/stutter" can come from asset streaming/slow RAM or HDD (or even a slow SSD perhaps?) -- I never had this issue in GTA5 (seems to be a pretty well optimized port in my personal experience as opposed to something like Batman Arkham Knight for example).

    Perhaps this is because the CPU gets overwhelmed when the game tries to load in everything at once so you get a microstutter til it finishes or some such, but I'm speculating -- it could also be due to slow RAM or a slow SSD/Harddrive, etc but correct me if I'm wrong ofc. I ask because I read a lot of comments regarding all this elsewhere online but there's often a lack of consensus or people saying opposite things from one another for these types of issues I find.

    I wish games would start doing what Gears 5 did with its menus where it tells you which settings have a GPU and which have a CPU perf impact and to what extent. That was so awesome of them to do imo.

    Thanks again for your time
     
    Last edited: Oct 26, 2019
  2. NewTRUMP Order

    NewTRUMP Order Master Guru

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    What cpu are you using?
     
  3. NewTRUMP Order

    NewTRUMP Order Master Guru

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    The CPU runs physics calculations and distance calculations to find what is around you, as well as if what you ran into stopped it. Certain games have the CPU do more tasks as well.
    The GPU does all the graphical calculations onboard, so it renders every image on your screen. Your weapon, its effects, your character, etc. are rendered by the GPU. It stores these textures in its VRAM, and does these calculations faster because the CPU is a general purpose computing device. The GPU is designed to do graphics calculations, and VRAM is faster than RAM, so it's calculations can be, and generally are, faster.
     
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  4. BlindBison

    BlindBison Master Guru

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    @NewTRUMP Order Thanks a lot, that's helpful. I have an 8700K at stock clocks currently.
     

  5. NewTRUMP Order

    NewTRUMP Order Master Guru

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    Sorry I forgot to ASK you what refresh rate your monitor is. To keep your micro stutter down it is best to cap your fps under the refresh rate. You can use Riva Tuner app and play with framerate cap amount in its settings.
     
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  6. Dragam1337

    Dragam1337 Ancient Guru

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    1. Texture quality uses a very slight amount of gpu power, as long as you got a sufficient amount of vram - when you exceed the amount of vram your gpu has, it starts to use shared memory aka the ram. When this happens the gpu performance hit can be rather massive, with severe stuttering as the vram swapping happens.

    2. Both.

    3. Depends. It varies from physics engine to physics engine, and from implementation to implementation. Most recent physic implementations mostly use the gpu, as consoles have very limited cpu power, thus it is easier to run simulated physics (such as the water in red dead redemption 2) on the gpu.

    4. Both.

    5. Gpu.

    6. Mostly cpu, but also a bit gpu.

    7. Depends on wether the particles are physics based, and if those physics are calculated on the cpu or gpu. But usually it will be gpu.

    8. Mostly gpu.

    9. Depends on the game engine - in a game like fallout 4 it is cpu, and in a game like shadow of the tomb raider it is gpu.
     
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  7. BlindBison

    BlindBison Master Guru

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  8. BlindBison

    BlindBison Master Guru

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    @NewTRUMP Order It's a 144 Hz G-Sync monitor -- I usually cap it to 141 inline with blurbuster's guide for avoiding the G-Sync ceiling. I've also got an older gaming laptop with a 60 hz panel, but I haven't seen stuttering on it that I recall. Thanks for the tip there, that's good to know.
     

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