Why do my fans rev up and down?

Discussion in 'Motherboards' started by Austion, Jun 9, 2019.

  1. Austion

    Austion n00b

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    I have a ASUS TUF Z390M-Pro and using a intel i7 8700 so i can't OC. The CPU is air cooled and runs around 134F, and i have 16GB of ram.

    When i open up a web page using chrome or any other browser the case fans will spin up for a few sec then spin back down. I have fan expert installed and have it set to silent all fans run around 800rpm CPU temp is at 134F.

    How can i keep my fans at 800rpm. The MB is controlling them all.
     
  2. Spartacus09

    Spartacus09 [H]ard|Gawd

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    Have you setup the smart fan profile in bios to define what speeds you want to run at which temps? That can sometimes override software control.

    That being said 134f is about 56c that seems really high for low cpu usage.
     
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  3. Austion

    Austion n00b

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    I didn't think it was that hot. How does water cooling do on a a PC that is on 24/7.
     
  4. Brian_B

    Brian_B 2[H]4U

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    If I recall, the BIOS can preemptively spin up a fan if it detects highs CPU load - that way the CPU doesn’t get so hot that it throttles.

    If the temps don’t go up or the load comes back down the fans will spin back down.

    It may be that the fan controller is using a different TC for temp control than what you are monitoring as well.
     
  5. mda

    mda [H]ard|Gawd

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    The answer is that the stock fan profile is too aggressive / responsive to CPU temperature.

    This happened too on my 2700X. You constantly hear the fans spinning up and spinning down, as opposed to a more constant fan speed that changes speed only gradually. The latter is less perceptible.

    You can solve this is by setting a higher baseline fan speed in order to slow down the instantaneous, big fan speed changes (it's this that is causing the noise).

    My fan profile at the moment - case fans (including the CPU fan) running at a flat 60% or so until 60C, then will ramp up to 75% nearer to 70-80C. You may want to experiment with different percentages as our case/CPU fans will likely have different sound profiles, but I hope you get the idea.
     
    Last edited: Jun 9, 2019
  6. Austion

    Austion n00b

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    I think your right i just hate the loud noise from only surfing the web.
     
  7. mda

    mda [H]ard|Gawd

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    Do the same on your board and the problem will go away :)
     
  8. SvenBent

    SvenBent 2[H]4U

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    use speedfan and set you own speed curve.
     
  9. Wade88

    Wade88 Limp Gawd

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    I set the curve in my bios the way mda does his, they almost never spin above 60% but when they do it's gradual. For radiator fans, case fans.
     
  10. Furious_Styles

    Furious_Styles [H]ard|Gawd

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    Yeah I'm leaning on not a fan curve problem but a poorly seated cooler or bad compound job. You should be in the 30C range at idle.
     
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  11. noko

    noko [H]ardness Supreme

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    I just found disabling fan speed control, having quiet fans to begin with and run them at full speed was way better than the changing fan speed, noise and temperatures. A consistent louder noise turned out to be better then a changing lower noise that speeds up and down. I do this now with all of my computers and not look back, just my preference.
     
  12. DeaconFrost

    DeaconFrost [H]ardForum Junkie

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    It's been taking me some time to play with settings before I get it right. It's a little frustrating, more so than it needs to be.
     
  13. Nenu

    Nenu [H]ardened

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    My PC is on 24/7 with an external 300mm rad (a car heatercore) and 2x140mm fans cooling only the CPU.
    The only issue I have is cleaning the radiator every 3 months and topping the water up. The loop has been cleaned probably 4 times in 14+ years.
    Cleaning the rad is made easy by not attaching the fans to it, they rest on top blowing down, the rad is supported a few inches off the floor, under the table.
    I use a brush vacuum attachment to suck the dust off.

    fwiw
    My PC is built inside a coffee table to hide it and keep it quiet, which is why I use an external rad to keep heat away from the gfx card which has an Accelero Xtreme III cooler.
    The Accelero cooler is so quiet it is always running full speed and the cooling performance is exceptional.
    I decided not to watercool the gfx card due to the expense of full card blocks plus the more complicated loop.
    And the Accelero coolers are so darned cheap and effective!
    This way I can get away with using an extremely quiet and robust pond pump, the Eheim 1048 (700+L/hr).
    (Eheim have now replaced this with the Universal 600 pump https://www.eheim.com/en_GB/products/technology/pumps/universal-600).
    It has been running 24/7 trouble free for at least 14 years, amazing.
     
    Last edited: Jun 17, 2019
  14. OliverQueen

    OliverQueen [H]Lite

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    I disagree as you can overclock the non-K SKU 8700 quite easily as I am doing it myself! Motherboard set itself to run at 46 x 102.3MHz with just the RAM set to run at XMP speeds. Didn't have to do anything else.

    As for the fan speed, I installed the ROG (also got same version installed on my TUF Z87 Sabertooth as well as my Z370 Maximus Hero) version of "Dual Intelligent Processors"/AI Suite & ran Fan Xpert wizard to set itself up. It set the fans to run at under 800rpm by default under the PERFORMANCE profile. With the Corsair AIO I idle at around 30C and only time the fans spin up is when encoding video (prolonged 100% cpu usage across all cores) & then it gets no hotter than around 60C after several hours of heavy encoding.
     
  15. Fremunaln

    Fremunaln Limp Gawd

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    If you run an ASUS board, UEFI probably has some [insert market name] Fan Controller built in as long as those fans are on the mb headers. Usually the default setup is perfectly fine, but softer ears and of course curiosity has folks to tinker. Many different adjustments around
     
  16. OliverQueen

    OliverQueen [H]Lite

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    That will be Q-Fan & if set to AUTO and then Fan Xpert permitted to run its configuration wizard, it will do an adequate job IMHO at both keeping the fan speeds low & cooling the system relatively well.

    One issue that nobody has mentioned yet is what fans are being used. If they are of a lower quality, then they will be louder even at low revs, same if they are dirty as well. I only have Corsair LL120, LL140 & ML140 fans in my system & I barely get a low hum at the lowest speeds & most of that is the air noise being pulled through the front mounted radiator of the AIO & the mesh dust filters on the Corsair Crystal 570X case. The fans on the GPU are louder at lower speeds than the chassis fans!