What does a MOBO need to be able to automatically control fan speed based on the temperature
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Motherboards
- Temperature
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Components
- Fan Speed
Last response: in Motherboards
Maxarini
August 26, 2014 3:48:46 PM
azguard4
August 26, 2014 3:53:03 PM
Maxarini
August 26, 2014 4:13:00 PM
Related resources
- What temperature reading does the CPU-fan use for control. - Forum
- Need help with automatically controlling fan speed. - Forum
- How many pins does a fan need to control its speed - Forum
Maxarini
August 26, 2014 5:21:27 PM
James Mason said:
Yes, it does need to be a 4 pin connector, usually referred to as PWM.Thanks for the reply!
Look at this: http://www.amazon.com/dp/B00K2RQAQY/?tag=pcpapi-20
I looked at the first picture and found some "ports". they were labeled "SYS_FAN1" SYS_FAN2" "SYS_FAN3" "CPU_FAN" and "CPU_OPT". Each of the ones I mentioned had 4 pins.
Does that mean this motherboard could do it?
Thanks again for the reply!
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Yes, that mobo supports voltage control of case fans connected to the chassis fan headers (SYS_FAN). You can use either 3pin non-PWM fans or 4pin PWM fans - either way, speed is regulated by voltage control based on your CPU temp and pre-programmed or user-programmed profiles set in your BIOS or using fan control software. Speed control on the CPU_FAN only works with PWM fans - if you hook up a 3pin CPU cooler fan to this header, it will run at 100% full time. The CPU_OPT works similar to the SYS_FAN headers in that you can use either type of fan and speed is controlled through voltage, but it's slaved to the CPU_FAN so it will mirror whatever duty cycle the CPU_FAN header is running at.
With modern mobos, to really tell what the CPU and chassis fan headers will do, you need to look at the header pinout in the manual. On the Gigabyte Z97X-SLI, all of the headers are 4pin, but the CPU_Fan is the only true PWM header. The rest of them use voltage control to manage fan speeds, regardless of whether the fan plugged in is 3 or 4 pin.
With modern mobos, to really tell what the CPU and chassis fan headers will do, you need to look at the header pinout in the manual. On the Gigabyte Z97X-SLI, all of the headers are 4pin, but the CPU_Fan is the only true PWM header. The rest of them use voltage control to manage fan speeds, regardless of whether the fan plugged in is 3 or 4 pin.
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Maxarini
August 27, 2014 12:28:27 PM
PWM fans on a PWM header receive a constant 12V. To adjust the speed of the fan, the mobo sends a pulse width modulation signal to the fan controller in the hub of the fan, which in switches the motor on and off very rapidly. The mobo (or fan control software by extension) can gauge the exact (or very close to exact) ratio of "on" time to "off" time needed to get the fan to rotate a designated speed. This allows a much finer degree of control than simple voltage adjustment. PWM fans can also idle at a lower speed than is possible with voltage control.
Voltage control works by raising and lowering the voltage applied to the fan. 12V applied results in the maximum speed capable. As the voltage is reduced, so is the speed of the fan. The mobo senses the speed via feedback from the tach wire (the third pin on a non-pwm fan), then adjusts the voltage as appropriate. There is more lag in control and more fluctuation in fan speed, since the voltage is constantly being adjusted to regulate the RPM.
If you're using a non-PWM header, usually it's better to use a non-PWM fan. A PWM fan will work on it, but unless it's a high-quality fan like a Noctua you may get clicks or motor whine. If you're using a PWM header, unless it's a dual function header like on some Asus boards, if you use a non-PWM fan it will only run at max speed, so a PWM fan is better.
Voltage control works by raising and lowering the voltage applied to the fan. 12V applied results in the maximum speed capable. As the voltage is reduced, so is the speed of the fan. The mobo senses the speed via feedback from the tach wire (the third pin on a non-pwm fan), then adjusts the voltage as appropriate. There is more lag in control and more fluctuation in fan speed, since the voltage is constantly being adjusted to regulate the RPM.
If you're using a non-PWM header, usually it's better to use a non-PWM fan. A PWM fan will work on it, but unless it's a high-quality fan like a Noctua you may get clicks or motor whine. If you're using a PWM header, unless it's a dual function header like on some Asus boards, if you use a non-PWM fan it will only run at max speed, so a PWM fan is better.
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Maxarini
August 27, 2014 2:56:56 PM
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Maxarini
August 27, 2014 10:20:58 PM
You'll have to check the hub to confirm this. It should have a 4pin Molex coming off it and connecting to your PSU for power. If there's another cable coming from it that has a regular fan connector on it (it may be currently connected to the case fan controller) you should be able to plug that into one of the mobo headers. Then you can control it via Speed Fan. Speed Fan can be finicky so you'll have to play around with settings if it doesn't detect it. Also, because they're all connected through the hub, Speed Fan or whatever software you use is only going to see it as one fan. If you want to control the fans individually, you'll need to skip the hub and connect directly to the mobo.
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Maxarini
August 28, 2014 12:14:49 PM
I looked at 2 threads
1: http://www.tomshardware.com/answers/id-2024335/nzxt-pha...
2: http://linustechtips.com/main/topic/85501-nzxt-phantom-...
They seem to be saying that the fan hub plugs into the power supply and the MOBO so it should work.
I have one more question though: I know that the MOBO knows the temperature of the CPU but what are the other component temperatures are monitored?
Thanks for doing all this. You really helped me a lot!
1: http://www.tomshardware.com/answers/id-2024335/nzxt-pha...
2: http://linustechtips.com/main/topic/85501-nzxt-phantom-...
They seem to be saying that the fan hub plugs into the power supply and the MOBO so it should work.
I have one more question though: I know that the MOBO knows the temperature of the CPU but what are the other component temperatures are monitored?
Thanks for doing all this. You really helped me a lot!
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Depends on the mobo, but it can report temps for pretty much any component that has temp reporting capability: HDD, SDD, DRAM, GPU, CPU, PCI expansion cards. Your best bet for figuring out all the ins-and-outs of temp monitoring is to go through your mobo monitoring tabs and see what's in there. Google or wikipedia anything that isn't obvious or can't be figured out from context.
Same thing goes for any monitoring software. All of them have different layouts and sometimes label things differently, with varying degrees of accuracy. The only real way to figure them out is to use them. Each of the major monitoring programs have tutorials available online.
Same thing goes for any monitoring software. All of them have different layouts and sometimes label things differently, with varying degrees of accuracy. The only real way to figure them out is to use them. Each of the major monitoring programs have tutorials available online.
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