CPU fan question

Hello, my BIOS has a cpu fan setting option, either variable or fixed. When fixed it blows at 100% all the time, when variable it gets faster the hotter the cpu gets.

What do you guys keep it on? are there any advantages/disadvantages to the different modes?

thank you!
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  1. You might want to try Speedfan, a free download. It will allow custom settings and manual override of the BIOS fan speeds. You can tweak the fan speed based on your preferences of cooling and noise.

    Instead you can get a Fan Speed Controller for as little as $20.
    http://www.newegg.com/Product/Product.aspx?Item=N82E16811998065&cm_re=fan_speed_controller-_-11-998-065-_-Product
    The above is a basic controller, you may want to search around depending on how many fans you will hook up to it (more fans = more power use). If you want to take extra caution in case someone (like a kid) tampers with the control knob you can use CoreTemp to have an automatic system shutdown in case temps go over a threshold you set manually, such as 65c.
    I think this is the easiest solution because you don't have to fiddle with BIOS settings and especially the Speedfan setup. Speedfan can be a challenge depending on your BIOS and motherboard.
  2. ^+1 for speedfan. Or you can control the fan on your BIOS.
  3. The only advantage to the variable speed is CPU fan noise reduction when the CPU isn't being used very much.
    I keep it on variable because the fan on high is noticable (AMD Athlon II x4 stock HSF).
  4. llmercll said:
    Hello, my BIOS has a cpu fan setting option, either variable or fixed. When fixed it blows at 100% all the time, when variable it gets faster the hotter the cpu gets.

    What do you guys keep it on? are there any advantages/disadvantages to the different modes?

    thank you!


    I normally set mine to variable if I don’t replace the fan. For the most part I replace the fan and have the controller on the case. I don’t think that there is a real advantage other than it’s not as loud.
  5. Use the speed fan it's a great programme and you can monitor your CPU , MOTHERBOARD , HDD , ICH and maybe the GPU ..........:-)

    When i want to play a game i always start speed fan and then start the game ....
  6. Well with the fan on high all the time the cpu will run cooler more often.

    with the fan on variable, the cpu will run a little hotter all the time, but it will be a more stable temperature range 37-55c compared to 27-55c.

    does that make sense? I know hardware doesn't like heating up and cooling down over and over, but is it worse than a slightly higher, but safe, temp?
  7. ^If your temperature is under 70C is good.

    Now, on idle a good temperature is 40 or less. In load 63C-65C, always under 70C.
  8. -You can buy a 5.25'' slot fan speed controller, however i recommend leaving your cpu fan and at least 1 case fan connected directly to the motherboard at full speed. Reason why is this:

    -Do you really want to trust the life of your system in a cheap fan controller?...

    -Oh and make sure to make it shut down if temps gets to high.
  9. Thanks for the help, my temps are good. The highest I ever saw it go was 62c during a stress test...but I never see it get higher than 55c while gaming.

    Will having it run between 37-55c be healthier than 27c-55c. because like I said, I know heat is bad for computer parts, but I also know big temperature changes are bad too. so is a higher idle temp with less of a gap preferred over a lower idle temp with more of a gap?
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