hysteresis behaviour 2D applications

Discussion in 'MSI AfterBurner Application Development Forum' started by Aragorn, Jun 12, 2021.

  1. Aragorn

    Aragorn Member

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    GPU:
    XFX RX480 8GB
    hi all

    i have this custom profile fans setting

    https://ibb.co/Z2gjc8P
    [​IMG]

    When i use the browser with "hardware acceleration on" the temp is always behind 50°C, but at ~45°C the fans ramp up for few seconds at random.
    Seem something related the hysteresis setting ....

    https://ibb.co/RPCbpDc

    How can i prevent this behavior ?
     
    Last edited: Jun 12, 2021
  2. gedo

    gedo Master Guru

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    According to your fan curve, the fan starts and goes straight to 35% (a rather high speed in my opinion) when temperature reaches 50°C. There seems to be a temp spike in your graph that would fit the bill.

    Hysteresis probably doesn't mean what you think it means.

    The "5°C" hysteresis means it requires the GPU to cool -5°C below the temperature seen at the last fan speed adjustment, before the fan speed is lowered. Up until that point the fan speed will only ever increase (if temperature rises). It takes a while for the temp to reach 45°C even with the high fan speed.

    *

    I think the biggest problem is that the start speed for the fans is so high (35%), so it's really noticeable against the silence of fans off.

    I'd suggest introducing an intermediate flat fan speed of around 20 - 28% for temperatures starting from around 45 - 50°C, and ending at 51 - 56°C. (Check the lowest PWM % where the fans spin at all, and add a couple of percentage points, or find an acceptably silent speed.)

    Then whenever a low load requires some cooling, the fan noise will be unnoticeable but will still offer enough cooling (and much more cooling than 0 RPM).
     
  3. Aragorn

    Aragorn Member

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    thanks for reply.
    I reduced 35% to 20% at 50°C and i'm going testing.

    Does the random fans revive is normal behavior when i use the browser ?
     
    Last edited: Jun 13, 2021
  4. gedo

    gedo Master Guru

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    It's not "random" if you've set fan profile that activates fan at 50°C and your GPU reaches 50°C. Just look at GPU temperature graph in your second image.
     

  5. Aragorn

    Aragorn Member

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    I found another problem after doing many tests.

    When the temperature touches ~ 70-71 ° C the fan FAN1 and sometimes also the FAN 2 go to maximum speed (~ 3500RPM) for a few seconds until the temperature returns to 69 ° / 70 ° C, so during gaming sessions the fan keeps increasing and decreasing speed ....

    The issue still persist also without afterburner running.

    driver version 465.89
    msi afterburner 464 Beta 3
     

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