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CPU overhead question

Discussion in 'General Discussion' started by konsic, Jan 11, 2019.

  1. konsic

    konsic

    Joined:
    Oct 19, 2015
    Posts:
    403
    I was playing other day one DX9 game made in UDK. What I noticed is: my CPU and GPU fans were quiet all the time.

    When I run my simple game scene built in Unity, not fully textured yet, CPU or GPU fans get really loud. This happens even in Unreal for simple game scene.

    I was wondering does new PBR rendering requires that a lot more power ?
    Could we get back to old DX9 era of performance for simple games which don't require that much performance-heavy machines but it feels like on modern engines they pull a lot of power from CPU/GPU.
     
  2. Zuntatos

    Zuntatos

    Joined:
    Nov 18, 2012
    Posts:
    491
    Basically, there's a couple options about how a game runs:
    A) limit framerate (vsync, cap) - it will only use the 'required' processing power, which may be less then you have available (thus sparing battery / power, generating less heat etc)
    B) limited by a single core (like slow game logic) - sort of pushing the pc, but not overall
    C) limited by all cores - cpu is maxed out to work at the framerate you're running
    D) limited by gpu - gpu is maxed out to work at the framerate you're running
    E) somehow you got the perfect balance and both are maxed out (adaptive quality can get here)

    your test scene is likely not using vsync or an fps cap, and thus fully using the cpu or gpu
     
    konsic likes this.
  3. konsic

    konsic

    Joined:
    Oct 19, 2015
    Posts:
    403
    How can I cap fps?
     
  4. Zuntatos

    Zuntatos

    Joined:
    Nov 18, 2012
    Posts:
    491
  5. xVergilx

    xVergilx

    Joined:
    Dec 22, 2014
    Posts:
    1,081
    Also, profiling the scene might help to understand what is going on better. Make sure to check it out.