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Bug 3080Ti, GPU load +50-100% with 1(!) particle rendered in scene (HDRP, 2021.3.11f1)

Discussion in 'Editor & General Support' started by DeadPoet, Sep 30, 2022.

  1. DeadPoet

    DeadPoet

    Joined:
    Jan 7, 2013
    Posts:
    39
    Hello everyone,

    My system started to get noticibly louder and hotter, so I checked my GPU load and o my, 50%+ on a 3080ti. I tried to figure out what caused it, found a) okay, my volumetric clouds are a huge load beast, which I will try to tame (any tips welcome) but b) as soon as any particles renders a particle the load jumps by 50%. I disabled my rain, mist, fires etc, they normally barely used anything. Turned only rain back on... turned the rain down to a single particle: Still +50% usage. Made a new one, 1 particle, zero other effects, 50% GPU load with no post processing or anything else active in the scene that could effect it.

    Any ideas? I can't work like this, it literally kills me (well, my electricity bill is), didn't have the problem with my old system (1080oc and 10 year old cpu). Drivers and everything are up to date, system only has problems in Unity with heavy load (even new games on max are not using as much GPU as this 1 particle is).

    Scene or game view doesn't matter, even play or no play. Nothing else is open. Sometimes it even pushes the GPU load to 90%+.

    /edit: Updating to 2021.3.11 in case it solves the/any problems
    /edit 2: Problem stayed the same after updating and reimporting all .vfx, testing it with old-school particles too.
     
    Last edited: Sep 30, 2022
  2. DeadPoet

    DeadPoet

    Joined:
    Jan 7, 2013
    Posts:
    39
    Okay. 2021.3.11f

    New HDRP Outdoor scene. Deleted everything, so empty. Gpu load is at 10%+. Why? What am I not seeing?

    New scene, sceneview, empty. Gpu 10%+
    upload_2022-9-30_8-0-5.png

    Original scene, sceneview, 0 Post Process, Lights, Particles. Gpu 10-30%
    upload_2022-9-30_8-2-3.png
     
    Last edited: Sep 30, 2022
  3. DeadPoet

    DeadPoet

    Joined:
    Jan 7, 2013
    Posts:
    39
    Gameview!

    No particles, with Post Process, Lights etc. Gpu 0%
    upload_2022-9-30_8-8-21.png

    Adding 1(!) Particle, doesn't matter which, can be rain, fire, a brand new one. Gpu load near 100% New bug, my particles are not even rendering anymore.
    upload_2022-9-30_8-9-39.png

    On my 1080 system 3 month ago, same projects I had 1.000.000 dust particles in a map with less than 1% Gpu load effect. What happened? (Tested 1 dust particle, same huge GPU load). Re-enabling my Volumetric Clouds also adds the same ~90% load on the GPU.

    upload_2022-9-30_8-15-26.png

    So far: Volumetric Cloud performance and 1 VFX Graph Particle both add ~ 90-100% GPU load permanently. Stacking them or just having one of them on is not changing the load really. 'Normal' particles have a similar effects, so non .vfx Also changing the primary and light steps in the rendering of the Volumetric Clouds from min to max value changes 0 on the load of fps it is using, which seems very odd.

    /e: After a restart and reimporting all my .vfx my GPU load is back to pre-update with ~ 50-60% instead of 90%+ for 1 particle. Still not barable.

    Game View Free Aspect 50%, Game View 1080p 98% GPU load. Tested on multiple systems.
    Even a new and empy scene with just 1 particle had 35% gpu load.
     
    Last edited: Sep 30, 2022
  4. DeadPoet

    DeadPoet

    Joined:
    Jan 7, 2013
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    Introducing Mr. Cube.

    When Mr. Cube is minding his own business in Game View the scene has ~55% GPU load.
    If you spin Mr. Cube like a mad man (for example with the rotation the the inspector) the GPU load goes DOWN to like 25-35%.

    Movement -> less GPU.... Anyone?

     

    Attached Files:

  5. DeadPoet

    DeadPoet

    Joined:
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    Posts:
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    Another problem, found by accident in the original project:

    Rain On (1 particle) / DoF ON | 95%+ GPU load
    upload_2022-9-30_11-25-51.png

    Rain Off / Dof ON | 0%
    upload_2022-9-30_11-26-18.png

    Rain On / Dof Off | 62%
    upload_2022-9-30_11-26-44.png

    Using DoF with a single particle pushes the GPU load by 30%+ (65% is still way too high)
     
  6. mgear

    mgear

    Joined:
    Aug 3, 2010
    Posts:
    9,554
    not sure if task manager gpu stats is very accurate in general?
    also, maybe editor itself will add all kind of extra cpu/gpu usage..

    also could check about vsync, if its on or off (and if its used in game view)

    how does unity Profiler view look like for those or unity stats panel (in game view)?
     
  7. DevDunk

    DevDunk

    Joined:
    Feb 13, 2020
    Posts:
    5,224
    Yeah the profiler might help.
    Maybe the effects are simple, but if it's a GPU bottleneck and you run at 500 fps the GPU still is heavily used. (The counter to this is limiting fps or vsync)
     
  8. DeadPoet

    DeadPoet

    Joined:
    Jan 7, 2013
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    Same problem in a new project in Unity 2022

    I tested my GPU temp and usage on the Nvidia tool too, and the fact that my card goes up to 80°C after a while in Unity is crazy. Not even raytracing games do that but an empty 1 particle scene?

    We tried V-Sync on an off (hoping that the limited FPS would help), but we already had it turned on. Limiting Frames in the Nvidia tool also didn't help.

    Is there any way to limit the FPS elsewhere?
     
  9. DeadPoet

    DeadPoet

    Joined:
    Jan 7, 2013
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    My biggest problem is the high load inside the editor / game view while working. I can't work 5 minutes without Unity overheating the card and crashing itself with a D3D error as soon as a single particle or cloud is inside the scene.

    Can I limit the fps in scene/game view pre play?

    (Maybe the old 1080 didn't have the problem because it never tried to render 200+ fps). We have the problem on all workstations at the moment, all having newer cards.

    Play Mode No Vsync 42% GPU
    upload_2022-9-30_11-58-39.png

    Play Mode Vsync 35% GPU
    upload_2022-9-30_11-59-38.png

    Scene View 68-99% GPU
    upload_2022-9-30_12-1-45.png
     

    Attached Files:

  10. DeadPoet

    DeadPoet

    Joined:
    Jan 7, 2013
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    Okay, I managed to get to 30-35% after using the Nvidia system control and setting the energy mode to normal and fps to 60 max (full system restart not only Unity until it worked). Funnily enough the FPS is only capped while at least 1 particle is active in the scene (cause the GPU doesn't have to render things?)

    The fact that a single particle is causing such a high load is still not normal though.

    No particle:
    upload_2022-9-30_12-31-27.png
     
    Last edited: Sep 30, 2022
  11. enhawk

    enhawk

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    Aug 22, 2013
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    835
    try turning this on (it's off by default) Screen Shot 2022-09-30 at 19.28.07.png
     
  12. DeadPoet

    DeadPoet

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    Jan 7, 2013
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  13. enhawk

    enhawk

    Joined:
    Aug 22, 2013
    Posts:
    835
    with unity 2021 & 2020 my GPU spins up to full speed when navigating the scene view. I think that view runs without Vsync and can't be changed. :/

    Perhaps previous versions of Unity Vsync'd the scene view... now it just runs at full speed even if empty.