Considering a new build. Suggestions are most welcome.

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Abula
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Joined: Tue Nov 02, 2004 12:22 pm
Location: Guatemala

Re: Considering a new build. Suggestions are most welcome.

Post by Abula » Sat Jun 30, 2018 8:46 am

To me its just that the fan is running in the extreme quiet zone, FanXpert is pretty good into predicting fan behavior but there are multiple samples and in some cases it might evaluate the fan way to close to the stop, i would just bump the first breakpoint (blue dot) to the 360 mark, so the fan is outside the extreme quiet zone, the fan should spin always if you do this or if thats your goal.

lodestar
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Joined: Fri Aug 05, 2005 3:29 am
Location: UK

Re: Considering a new build. Suggestions are most welcome.

Post by lodestar » Sat Jun 30, 2018 11:07 pm

Foggy wrote:...This is an Asus motherboard. The fan is not hooked into CPU-OPT. It's hooked up to chassis fan 2. I checked the BIOS and all the fans are set to minim 200 rpm. All the settings are Auto, so I have not chosen PWM or DC. Should I?
You could try setting this fan to PWM rather than Auto.

Olle P
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Joined: Tue Nov 04, 2008 6:03 am
Location: Sweden

Re: Considering a new build. Suggestions are most welcome.

Post by Olle P » Wed Jul 04, 2018 3:48 am

Comparing the fan's speed spectrum, as presented by Lodestar above, to what the motherboard tries to achieve it's logical that the motherboard will shut the fan off every now and then while trying to make it run slower than possible.
The solution is to not use any speed setting between 0 and 350 rpm in the mobo's fan curve. (Shift the 40 degree marker either down to zero or up closer to 360 rpm.)

The alarm is typically available for the CPU fan header only.

lodestar
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Joined: Fri Aug 05, 2005 3:29 am
Location: UK

Re: Considering a new build. Suggestions are most welcome.

Post by lodestar » Wed Jul 04, 2018 5:42 am

The fan profile shown by Fan Xpert seems to me to be showing that the Auto fan mode select has picked Voltage rather than PWM mode. As a consequence the minimum fan speed is right on the boundary between the fan running or not. This would explain the on/off effect on fan speeds that is being observed. The solution as already suggested is to either to set the fan to a higher speed, select PWM mode rather than Auto for the chassis fan header it is connected to or plug it into the currently unused CPU_OPT fan header. Having a fan that runs at a slower speed in Voltage mode than it does under PMW is unusual but it has been seen before with some Scythe models and I think the Kaze Flex 1200 PWM is another of them.

Foggy
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Joined: Sun Nov 26, 2017 1:53 pm
Location: Norway

Re: Considering a new build. Suggestions are most welcome.

Post by Foggy » Sun Jul 08, 2018 11:08 am

Excellent advice guys!

Things seem to be working better now.
To me its just that the fan is running in the extreme quiet zone, FanXpert is pretty good into predicting fan behavior but there are multiple samples and in some cases it might evaluate the fan way to close to the stop, i would just bump the first breakpoint (blue dot) to the 360 mark, so the fan is outside the extreme quiet zone, the fan should spin always if you do this or if thats your goal.
I did this.
You could try setting this fan to PWM rather than Auto
And this.

After at did these things, I have not noticed any fans stopping :)

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