# Define r6 useless fan hub, runs at same speed as cpu (%)



## gasolin (Feb 25, 2018)

Why does the define r6 fan hub only works when you connect it to a cpu fan header and accept that the fan speed from the case fans is the same as the cpu fan speed (%).

I want to adjust the speed of the fans connected to the fan hub independent from the fans on my noctua nh-d15 se am4 cooler.

I want to run my case fans at let's say at 700omd (Fractal Design Dynamic X2 GP-14 minimum speed is 60% around 700 rpm) no matter what speed my cpu cooler runs at (connected to my mb), using the fan hub i can't do that, it only works using a cup fan header and then cpu and case fans run at same speed (%)

Also a problem is that i can't se the speed of the case fans when i use the case fan hub, only speed i can se is from my cpu cooler connect to the cpu fan header on my mb


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## newtekie1 (Feb 25, 2018)

The hub is just a normal PWM fan hub, you can plug it into any 4-pin PWM fan header on your motherboard.  If you want to plug it into a 4-pin case fan header, then do that, and you can then control the fans connected to the hub independently from your CPU fans by adjusting the speed of that case fan header through your motherboard's BIOS or software.

I believe the fan hub will only report the RPM of one of the fans connected, as there is no way to report all of them.  I think it reports the speed of #1 fan port on the hub.


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## gasolin (Feb 25, 2018)

It doesn't, manual say connect it to a cpu header,no rpm readings in the bios when connected to a chassi fan header Define r6 manual


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## Hockster (Feb 25, 2018)

If you want to control each fan independently you need a controller with it's own software. Something like the Corsair Commander or NZXT Grid+.


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## newtekie1 (Feb 25, 2018)

gasolin said:


> It doesn't, manual say connect it to a cpu header,no rpm readings in the bios when connected to a chassi fan header Define r6 manualView attachment 97678



You only have to connect it to the CPU header if you are connecting your CPU fan/s to it.  But it can go in any PWM fan header, the function is the same.  That hub might not report RPM speed now that I think of it, I don't remember, but it could also be that the Chassis fan header on the motherboard isn't reading it properly.  Not all chassis fan headers read PWM fan hubs RPM properly. It doesn't really matter, if you want the fans to run at 60%, then set the chassis fan header to 60% and the hub will run the fans at 60%.


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## xkm1948 (Feb 26, 2018)

I never use the included fan hub. Even for 3 pin fans you can do customized fan curve. Using a DefineR5 with default fans all plugged into MoBo fan headers. Works great. This also allows you to set independent fan curve for each fan.


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## erixx (Feb 26, 2018)

+1 I already have had several mobos that come with a fan-hub pcb and never used them. If you want it follow the tips given by newtekies1


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## newtekie1 (Feb 26, 2018)

xkm1948 said:


> Even for 3 pin fans you can do customized fan curve.



You'd be surprised how many motherboards don't support speed control on 3-Pin fans anymore.


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## eidairaman1 (Feb 26, 2018)

I prefer rheostats for total control of my case fans, only the cpu fan revs up the rest stsy quiet lol.


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## gasolin (Feb 26, 2018)

newtekie1 said:


> You'd be surprised how many motherboards don't support speed control on 3-Pin fans anymore.



Asus does, all those i have had for the last 2-4 years did


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## Jetster (Feb 26, 2018)

I didn't think any three pin MB header has PWM


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## gasolin (Feb 26, 2018)

Jetster said:


> I didn't think any three pin MB header has PMW control.
> 
> Hence the fan controller



Speed control on 3 pin fans are not problems with asus mb's


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## Vario (Feb 26, 2018)

gasolin said:


> Why does the define r6 fan hub only works when you connect it to a cpu fan header and accept that the fan speed from the case fans is the same as the cpu fan speed (%).
> 
> I want to adjust the speed of the fans connected to the fan hub independent from the fans on my noctua nh-d15 se am4 cooler.
> 
> ...


The way that fan hub works is using duty cycles; the motherboard header sends a PWM signal through the hub to the CPU Fan, which switches the fan on and off at a high rate of speed, this spins the fan up to a target range.  The motherboard header receives the tachometer output from the CPU fan as a feedback and adjusts PWM signal as needed to raise or lower speed (via PWM switching duty cycle).  The PWM wire is bridged off of the CPU fan through the hub and goes to each of the fans on the hub, the result is the other fans do not report their tachometer output to the motherboard and they are slaves to the primary fan's CPU PWM duty cycle.  Naturally, this type of fan hub only works with 4 pin fans.  I use a similar system with a wiring harness I made myself which has a common 12v, ground to the power supply directly and the PWM wire is in parallel to each fan.  The tachometer and originating PWM wires from the lead fan goes to the motherboard's fan header.  This type of system works well if all the fans are near identical so they run at similar RPMs, generate the same sound volume levels and air flow + pressure.

My current motherboard has many PWM fan headers so it is quite easy to set a nice fan control curve.  I made a few harnesses as described above and slave all the identical fans together to one header per fan type, and I adjust the target % curve so that they output a reasonable level of sound each.  My 140mm fans run at a lower speed than my 120mm but output more airflow so I try to balance everything out so that the sound level is manageable to listen to and the airflow is ideal.


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## gasolin (Feb 26, 2018)

Vario said:


> The way that fan hub works is using duty cycles; it sends a PWM signal to the CPU Fan, which switches the fan on and off at a high rate of speed, this spins the fan up to a target range.  It receives the tachometer output from the CPU fan as a feedback and adjusts PWM signal as needed to raise or lower speed (via PWM switching duty cycle).  The PWM wire is bridged off of the CPU fan through the hub and goes to each of the fans on the hub, the result is the other fans do not report their tachometer output to the motherboard and they are slaves to the CPU PWM duty cycle.  Naturally, this type of fan hub only works with 4 pin fans.  I use a similar system with a wiring harness I made myself which has a common 12v, ground to the power supply directly and the PWM wire is in parallel to each fan.  The tachometer and originating PWM wires from the lead fan goes to the motherboard's fan header.



So i can't have a fixed rpm using the fan hub like having, let's go to an extreme and say 9 fans at 300 rpm instead of 3 fans at a rpm of  max 1000 rpm (which are max rpm from the stock dynamic x2 case fans)


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## Vario (Feb 26, 2018)

You can, by experiment you find out what duty cycle % in your motherboard will generate 300 rpm, you have all identical fans, and you set that duty cycle as a constant and it will run them all at 300 rpm +/- a few RPM depending on how efficient your fan's internal PWM controller is.  You can probably bridge many many fans in parallel off that single PWM wire but eventually the signal will be weakened.


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## xkm1948 (Feb 26, 2018)

Interesting. At least for my ASUS X99 and the recent MSI X399 both allow custom fan curve profiles on 3pin fans


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## RejZoR (Feb 28, 2018)

Connect it to some other fan port that you set up in BIOS to behave differently? My old ASUS Rampage II Gene had such functionality, I know new ones have more. Or just configure all the headers on mobo and use those to control fans. It's how I had it on my ASUS X99 and now on MSI X99. Both fairly similar, except MSI now has less fan headers so I had to improvise. But in the end it still works. Ultra silent during small loads and slightly nosier under full load. I have my "zones" in the case individually configured. CPU for example is based on CPU load, but the rest doesn't have to ramp up unless temperature rises which is indication of load on grpahic card. So, CPU is based on load where the rest is based on internal temperature of the case. Which makes less fan speed fluctuations during gaming and makes sure to cool the case down even after gaming is complete because load does drop, but temperature doesn't and the fans continue to work till it goes to idle temps. It works really well. The top case fans are based on PSU load because I ran out of fan headers. I need those to run at very low RPM just so they force air to move upwards inside the case faster. And it seems to work quite well.

When you figure out a smart setup for your case you can make incredibly quiet system that can be properly high end. I don't think I've ever owned a quieter and more powerful system than I have now thanks to clever cooling I've done to my system. And it's on a budget so to speak. I have a rather cheapo case from Corsair. Apart from non removable HDD cage, it's perfect and has cost me next to nothing lol.


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## gasolin (Mar 26, 2018)

Update 3 x120mm in front of my pc, stock speed on my cpu,gpu, i wanted more airflow since the gpu i have now is faster,hotter then my old card and only 2 fans (instead of 3), fans are 3 pin, dc, i set the fans to pwm an now it works but i still can't se rpm in HWmonitor or my bios. About 50-60% for the front fans stock ryzen 1700 8-10% usage 30 c, that is something the fx 8300 couldn't match at all, cpu cooler at 530 rpm.


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## Deleted member 67555 (Mar 26, 2018)

You can't change the bios fan setting from CPU_PWM to CPU_FULL or something like that???


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## gasolin (Mar 26, 2018)

On DC in the bios they run at full speed, it has to be PWM in the bios.


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## John Naylor (Apr 20, 2018)

I use the Phanteks fan hubs like this:

Channel 0 = CPU and CPU_OPT Headers => dual water pump
Channel 1 = CHA_1 header to Fan Hub 1 => (6) 140mm fans on 420mm radiator
Channel 2 = CHA_2 header to Fan Hub 2 => (4) 140mm fans on 280mm radiator
Channel 3 = CHA_3 header to Fan Hub 3 => (6) 140mm case fans

- All fans are 3 pin DCV, the hub accepts either PWM or DCV input
- Each channel has its own temp / rpm curve
- All rad fans turn off if temp curve asks for less than 350 rpm
- All rad fans have a ramp down delay ... when load drops, coolant is still hot so speed ramps down slowly over 60 seconds to remove that latent heat... also eliminates ran speed chasing its tail under varying loads.
- Using 1250 rpm fans on a PWM header, you can connect up to 11 fans to the hub using the supplied SATA power cable.
- Using 1250 rpm fans, on a DCV or PWM header you can connect up to 6 fans to the hub without using the supplied SATA power cable.

All fan curves created using MoBo fan control utility and rpm can be read in same utility


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