if cpu and system running cool will PWM fan shut down?

newbuild · 2 Dec 2013 at 09:39

i'm running temps between 21 and 29c on the cpu and system. on a couple of occassions the exhaust fan has stopped spinning - is this as a result of the system running so cool or a fault possibly?

i ask becuase when i went into the gigabyte app which controls the fans and did calibrate and then flicked between standard and silent modes it kicked again and stayed on...............

newbuild · 2 Dec 2013 at 11:42

so i maybe driving the fan with voltage as opposed to the PWM profile?

newbuild · 3 Dec 2013 at 20:51

Tealc said:
If you drive the fan with voltage rather than PWM then it is entirely possible that a PWM fan will stall or not start up.

Generally a PWM duty cycle of 20 or 30% will drive the fan at it's lowest rated speed and should start up because the 12v kick of PWM should overcome the inertia of the fan bearing.

how can i check if the fan is running on pwm as opposed to voltage?

newbuild · 4 Dec 2013 at 14:36

abbotsmike said:
If your board is the one in your sig, then you only have one PWM fan header, the CPU_FAN header. The others (CPU_OPT and SYS_FAN1/2/3) are all voltage control.

Confusingly, they are all 4 pin headers anyway. This means that while they will drive PWM fans happily, they are not controlling them via PWM.

so in that case and thank you for pointing this out i've gone and bought the wrong type of fans for my board, i actually asked gigabyte this questio about 3 pin and 4 pin fans. and they told me that the board was unable to adjust the speed of 3 pin fans but it was able to manage 4 pin PWM fans.

so how can i get around this now?

newbuild · 4 Dec 2013 at 14:40

i am just using the gigabyte app which is not very good in my opinion. any suggestions on a 3rd app/software to ensure the fans are being managed and ran correctly.

newbuild · 4 Dec 2013 at 15:43

so it looks like i need to run these fans based on voltage as opposed to PWM. think i should just get a fan controller to do this?

newbuild · 4 Dec 2013 at 19:23

Tealc said:
You could get yourself a PWM splitter cable (or two) and have the PWM fans all controlled off the CPU_FAN header. I suppose Gigaybyte implement 4 pin fan headers so that all available fans will fit to their boards but it is cheap that they don't implement control circuitry for modern PWM fans at the same time.

doing ths wont have any sort of adverse affect on the fans or place stress on the board or anything?

newbuild · 6 Dec 2013 at 19:53

i have decided to buy the Lamptron FC5V3, what you guys think serve my purposes well?

newbuild · 6 Dec 2013 at 20:40

to be honest i think regarding this fan/cooling stuff i'm out of my depth can't get my head around it, and added to this is that sometimes my exhaust fan comes on sometimes it don't and that's same with the front two as well. which is making me feel paranoid.

newbuild · 9 Dec 2013 at 07:07

abbotsmike said:
Have you got any easytune set up controlling the fan profile? It might be that the software will drive a very low voltage that your fans just will not switch on at. Fans can be a bit unpredictable at lower voltages. In the right conditions they may start spinning at say 5v, but then other times not until 7v. You got a link to the exact fans you are running? Also, what fans are plugged in where on the mobo?

i have this http://www.noctua.at/main.php?show=productview&products_id=64&lng=en on the cpu_fan and two of these in the front of the case and one in the exhaust http://www.noctua.at/main.php?show=productview&products_id=65&lng=en the exhaust is plugged into sys_fan 1 and the front two are in sys_fan 2 and 3.

in the BIOS they are are setup on normal with a 0.75% slope i think thats what it is.

Bart_Hunt said:
You can setup stuff like that in bios, right?
Every decent board have pwm fan support and pwm fan profiles in bios.
My heatsink fans were spinning slow so i simply went to bios and changed the profile to turbo.
Easy.
Rest of the fans are on fan controller, but they arent pwm fans, just regular ones.

only the cpu_fan is PWM enabled all the other fan connections aren't PWM enabled they are voltage controlled/driven.

newbuild · 9 Dec 2013 at 07:26

abbotsmike said:
Have you got any easytune set up controlling the fan profile? It might be that the software will drive a very low voltage that your fans just will not switch on at. Fans can be a bit unpredictable at lower voltages. In the right conditions they may start spinning at say 5v, but then other times not until 7v. You got a link to the exact fans you are running? Also, what fans are plugged in where on the mobo?

do you think this would be a good addition and solve all my issues BitFenix Recon Fan Controller, the option of controlling and monitoring is appealing.