Phanteks PWM Fan Hub issue

PapaLazaru

PapaLazaru

PapaLazaru

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I've got the cable plugged into the CPU OPT header and it works fine with all the 3 pin case fans (5), but my front CPU fan which is 4 pin and plugged into the hub, onto works intermittently. It is almost like it is not getting enough juice. It is like this even when gaming and all the other fans spin up to keep everything cool. Sometimes it works, sometimes when it doesn't.

Any ideas?
 
I've noticed that some 4 pinners just don't tolerate low voltage like 3 pinners can. There's a fair bit extra electronics stuff on a PWM fan compared with a 3 pin fan, maybe some of it prefers the 12v goodness. One of mine wouldnt kick over until 8.5v which was crazy.
 
Thought it might be something like that.

Do you reckon it is safe to use 3 PINS fans on the cooler if using the hub, ie do you trust it to manage the speeds enough for the cooler?
 
If it works like my own circuit, and I'm not wholly sure it does as there are a few differences, then once pwm hits 100% the fan should be near 100% too. Verify with CPU cooler fan in master fan slot and verify fan speed to PWM.
 
You don't have a Phanteks PWM hub issue. You have a PWM fan on 3-pin control issue. :D
While some also work well on variable voltage, some just don't like it. After all, PWM fans are designed for pulsed 12v power control, not for variable voltage control. :D
 
I thought that might be the case. Problem is one PWN CPU fan is in the CPU header and the hub is in the OPT header with all the other fans plugged into it including the other 4 pin CPU fan. I can't be sure they would even spin at the same speed?

Would you dare use 3 pin fans all round?

These are the connectors on the mobo -

1 x CPU Fan connector(s) (4 -pin)
4 x Chassis Fan connector(s) (3 x 4 -pin, 1 x 3 -pin)
1 x Optional Fan connector(s) (4 -pin)

Would the hub do it's thing if plugged into a 4 pin chassis fan connector instead?
 
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I've been using my PWM to dc controller circuit for my CPU fan for many years. The Phanteks design is similar to mine albeit with 2 sides to the circuit, master and everything else, oh and theres no user adjustments with the Phanteks.

It's a setup and forget system that will work pretty much forever provided it isn't overloaded or short circuited.

Ive considered buying a Phanteks to see how well, or badly, it works but wouldnt use it instead of my own design, as you can't improve upon perfection ;p
 
We don't know for sure you have PWM on CPU opt fan header unless you have the the Sata cable connected to PSU.

PWM headers can be split on a 'Y'-splitter. The PWM signal on pin-4 will control both the Phanteks PWM hub and a PWM fan or three.

You can use all 3-pin fans if you want.

Just because a header is 4-pin does not mean it is PWM. Very few motherboards have PWM chassis fan headers. In other words the hut would only work with sata power if it is a PWM head.
 
PapaLazaru said:
That is all good but it does not help me. :D

Will it work on a 4 pin chassis fan connector? Assuming it is 4 pin for a reason?
Click to expand...
You can make the assumption that a 4-pin fan header is PWM, but 999 times out of 1000 it is won't be. ;)

Edit: Tealc makes a very nice PWM control for 3-pin fans. :D
 
PapaLazaru said:
Yep.

Hub plugged into a sata off the psu and hub plugged into the cpu opt connector. One 4pin cpu fan in 'fan 1" on the hub then all the chassis 3 pins also plugged to the others.
Click to expand...

Than it is working using the PWm signal from CPU fan header. :D

Sorry for the confusion. Many (not sure if all) of these Phanteks PWM controlled fan hub can also be used as 3-pin variable voltage fan spitter hubs. But if the Sata power is connected the fans will only run at full speed. ;)

For fan speed to be controlled when the Sata power is used there must be a PWM signal from motherboard fan header (some fan controllers have PWM headers too) pin-4 to hub. This signal is what regulates the fan speed.

I'll stop .. probably just confusing you with information that isn't needed. :o
 
The Phanteks PWM fan hub I saw (a few photos of the PCB provided by Doyll in fact) has effectively 2 drive circuits. The first drives just one fan using a NPN/PNP inverter circuit and smooths the voltage using a capacitor. The second outputs a PWM signal level shifted from 5v to 12v using a NPN/P-ch Mosfet configuration, possibly smoothed a touch.

The first circuit and second circuit are therefore separate in effect and will react differently depending on what sort of loads you throw at it. A low current fan on master channel may spin faster than is ideal, while a high current fan may run too slow, or not at all unless the PWM duty cycle is ramped up. It was for this reason that when I designed my circuit I added a user adjustable potentiometer that allows you to dial in your own sweet spot. I assume Phanteks didn't bother with this as it would make it too complicated for the end user and went for a one size fits all solution

As Doyll mentions PWM does not always feature of 4 pin headers. On my mainboard I have 6 headers, all 4 pins yet only the CPU_FAN has any form of PWM or voltage control.

However if your 3 pin fans are being controlled when attached to the PWM hub then you can assume in your case that the OPT header is putting out some form of PWM, otherwise they'd run at 12v continually as you are feeding in an independent 12v source.

Edit: Almost like a double post there between Doyll and myself. May be confusing the issue further...
 
Thanks for both of your inputs, it really has been a help. I am going to buy a few bits to get my case finalised so this can include fans if needed.

I am sure the OPT header is sending out a PWM signal, I would expect it to as I have always run 2 CPU cooling fans and one has always been plugged into the CPU fan header and the other into the CPU OPT header and they speed up and down in unison.

I might just bite the bullet and plug both CPU cooling fans back into their old headers and plug all the case fans through the hub and into a 4 pin chassis fan header. As long as it is quiet when idle and I can hide all my cables it is all I want really and was the main purpose of the hub, though it does without doubt lower the ambient noise in the case when idle which is an added bonus. It is silent at idle which was not the case before.

Alternately I can just swop out my 2x 4 pin CPU fans for 3 pin fans and then have all the fans running through the hub into the main CPU fan connector, though this will cost more money and I am really not sure if that is to be trusted as 3 pin fans are not really meant to be variable are they not?

*edit* I have a couple of brand new Corsair 3 pin 120mm fans at home somewhere though think they might be more aimed at case cooling than CPU cooling.
 
PapaLazaru said:
Thanks for both of your inputs, it really has been a help. I am going to buy a few bits to get my case finalised so this can include fans if needed.

I am sure the OPT header is sending out a PWM signal, I would expect it to as I have always run 2 CPU cooling fans and one has always been plugged into the CPU fan header and the other into the CPU OPT header and they speed up and down in unison.

I might just bite the bullet and plug both CPU cooling fans back into their old headers and plug all the case fans through the hub and into a 4 pin chassis fan header. As long as it is quiet when idle and I can hide all my cables it is all I want really and was the main purpose of the hub, though it does without doubt lower the ambient noise in the case when idle which is an added bonus. It is silent at idle which was not the case before.

Alternately I can just swop out my 2x 4 pin CPU fans for 3 pin fans and then have all the fans running through the hub into the main CPU fan connector, though this will cost more money and I am really not sure if that is to be trusted as 3 pin fans are not really meant to be variable are they not?

*edit* I have a couple of brand new Corsair 3 pin 120mm fans at home somewhere though think they might be more aimed at case cooling than CPU cooling.
Click to expand...
To me the best way to go is to use a simple PWM 4-pin 'Y'splitter for your PWM CPU fans on CPU fan header. That way both CPU cooler fans run the same and if case fans are running at a different rpm who cares? Most all of my systems have case fans running lower speeds than CPU fans .. definitely lower than GPU fans. Honestly, fan rpm means nothing. Their airflow and noise level is all that is important. I don't care if a fan is spinning 500rpm or 1000rpm as long as it's supplying the air needed to keep things cool and isn't making any noise. :D Looking at the fans' actual rpm is mostly 'bling', not function.

Only time the rpm is useful to me is setting up different fan curves .. and then only because I know what rpm give what cfm an dBA .. the latter two being what's important. :p
 
Had not thought about that and it makes perfect sense.

I'll run both 4pin CPU fans off a splitter into the CPU fan header and run all the case fans through the hub into the CPU OPT header.

Fixed! And thanks.
 
This is weird, so until I get the splitter I have just been running it as before, sometimes the 4 pin fan in the hub spins up, sometimes it does not. When it does not spin up, neither does the other CPU fan, which is not even plugged into the hub!

Plugged the hub into a chassis fan connector for the time being and plugged the CPU fan back where it belongs.

It is so noisy again though.
 
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