(ASUS M4A78LT-M) Fans running full speed despite Q-Fan being enabled


recently got a new computer with this motherboard in it and for some reason Q-Fan doesn't seem to be doing its job. It's enabled in the BIOS, but the chassis fan is running at 3000+ RPM and the CPU fan at about 2800+ RPM. Temperatures are at about 30 degrees celcius, and Q-Fan is set to kick in to full speed at 60 degrees celcius.

What can I do? Please, any help would be greatly appreciated.

4 answers Last reply
More about asus m4a78lt fans running full speed enabled
  1. Q-FAN only works with fans that utilize 4-Pin PWM controls, and are of course connected directly to the motherboard.

    If you don't have these, it won't do anything,
  2. Not having opened it up yet, and unfortunately not being around the computer right now, I'm unable to tell whether it does have an appropriate fan - I just presumed, since the motherboard is able to read and report the fan's speed values in RPMs, that they should be able to be controlled too.
  3. Some motherboards do control the fans by RPM monitoring, but Q-Fan is not one of them. It controls by power output, and uses PWM to ensure accurate controls.
    When it comes to fan connectors:
    2pin = Power only
    3pin = Power and RPM monitor
    4pin = Power, RPM monitor, and PWM control
  4. You can control 3-pin fans but you need to associate the fan with a temperature and the motherboard will change the voltage on that fan to try and reach that target temperature. I believe you can also specify a specific voltage for the fans too. usually between 8-12 volts.
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