PWM too fast.

P4Clock

P4Clock

P4Clock

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This is 100% in the wrong place but i dont know where to put it, i trust an Mod will move it :) Also sorry for posting in wrong place

And now on with the question.
i have 6 AC f12 pwm fans in my system and for some reason the minimum pwm speed the system will run them at is 1100rpm it sounds like my pc is a jet engine.
i have used them in other systems and been very happy with them running down to 300rpm.
It as to be a problem with my motherboards pwm controller, if i put a small resistor into each fans red wire would the pwm still function?
 
Have a look in your bios for a fan control screen. On my asus motherboard there is also software which was bundled with the motherboard which allows you to change the fan curves. For pwm fans you need to be looking for the pwm option, changing this should slow the fans down
 
wildman_33 said:
Have a look in your bios for a fan control screen. On my asus motherboard there is also software which was bundled with the motherboard which allows you to change the fan curves. For pwm fans you need to be looking for the pwm option, changing this should slow the fans down
Click to expand...

yes i know. my setting are.
Target temp: 70c (i maxxed it to see if the cpu was running hot, there was no change)
Target Fan speed: 25%

fan is rated to 300-1350rpm its running at just under 1100rpm
 
Is any of this software giving you actual PWM duty cycle values? You might have a mismatch of different control methods.

You can use a resistor to drop the 12v down to something lower but the problem will still remain and you'll be sacrificing your top end speed.

I know Speedfan works quite well and allows manual by duty cycle percentage control of CPU PWM if set up correctly.

PWM implementation is very simple and I'd have thought it would either work or not work. Now considering it works at some level suggests to me that its à conflict, or using voltage control but not going very low.
 
i know my mobo as 3 pwm headers cpu, sys1, sys2. now i do know system fans 1 and 2 have no pwm control it just voltage control even thought its a 4 pin header.

the cpu pwn has allays worked just no very good, you can set the duty cycle percentage in bios, but any setting under 50% will not work. and with some fans it will not go used 75%
 
i have found that the MSI control centre will let me set up a fan profile where all 3 PWM headers work as they should, But i have to open the program and load the file manually ever time i power on the pc
 
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