Gigabyte Mobo fan headers only .5amp output dilemma

donfm

Senior member
Mar 9, 2003
677
0
71
I own a Gigabyte GA-Z170X Gaming 7 v1.0 mobo and I was surprised to find that the 3-SYS_FAN headers only are rated .5amp each. Gigabyte support says NOT to use a splitter cable. Considering this is supposed to be a gaming board and gamers need extra case fans for cooling the GPU this creates a problem. My Corsair Case allows up to 7 case fans. Other boards have a 1 amp ouput on the fan headers and are thus splittable.

I currently am looking for an external fan header that controls multiple 3 pin identical, .18 amp rated, non PWM, case fans using power directly from the PSU, with voltage speed control from a single SYS_FAN header to auto control all the fans speed based on board temp. I am unable to find any such add on header that does this. All the speed control headers are either PWM or they give you a high/low slider switch to manually control the fan speeds for 3 pin fans. You can get an external 5.25 fan panel the you adjust manually with knobs but I am looking for an automatic solution controlled by the mobo SYS_FAN header.

Seems like my only option is to run the 3 pin fans constantly at top speed or get PWM fans. I did find a header that speed controls multiple PWM fans from one 4 pin onboard fan header.

Do they even make such a thing?
 

LTC8K6

Lifer
Mar 10, 2004
28,520
1,576
126
If the fans are .18 amp, then it should be perfectly safe to connect two of them to a .5 amp rated header?
 

donfm

Senior member
Mar 9, 2003
677
0
71
If the fans are .18 amp, then it should be perfectly safe to connect two of them to a .5 amp rated header?
Thanks for your response. Gigabyte support told me I cannot put more than one fan on the fan header and not to use a splitter cable. Now that could be just some level 1 tech support guy covering his arse if the header burnt out.
 

aigomorla

CPU, Cases&Cooling Mod PC Gaming Mod Elite Member
Super Moderator
Sep 28, 2005
21,087
3,598
126
Thanks for your response. Gigabyte support told me I cannot put more than one fan on the fan header and not to use a splitter cable. Now that could be just some level 1 tech support guy covering his arse if the header burnt out.

theres a lot of reason why tech support told you not to do that..

1. The RPM Signal on the fan will get garbled if you use a splitter.
It will take 2 senses and garble it, making your fan curve setting in bios go wack.

2. even tho .18+.18 = .38 and it seems fine to put it on a .5V header, HOWEVER that is run amperage.
Fans and motors have something called startup amperage where the fans pulls more then what its raited at startup.
This is why a lot of fans can run @ 5V yet they can not be started at 5V. So with constant on and off's you may or can burn out that header.

3. just save yourself the peace of mind and get a splitter like this:
https://www.amazon.com/SilverStone-...8&qid=1517254376&sr=8-9&keywords=fan+splitter

you can put 3 pin fans in it, even tho it is meant for pwm... the 4th cable is just a pwm sense line.
it has a capacitor built in for stuborn fans that overdraw current @ start votlage... what i mentioned in statement 2.
and it uses a SATA power port to power the thing so you dont need to break out a 4pin standard molex if nothing is using it.
 

donfm

Senior member
Mar 9, 2003
677
0
71
theres a lot of reason why tech support told you not to do that..

1. The RPM Signal on the fan will get garbled if you use a splitter.
It will take 2 senses and garble it, making your fan curve setting in bios go wack.

2. even tho .18+.18 = .38 and it seems fine to put it on a .5V header, HOWEVER that is run amperage.
Fans and motors have something called startup amperage where the fans pulls more then what its raited at startup.
This is why a lot of fans can run @ 5V yet they can not be started at 5V. So with constant on and off's you may or can burn out that header.

3. just save yourself the peace of mind and get a splitter like this:
https://www.amazon.com/SilverStone-...8&qid=1517254376&sr=8-9&keywords=fan+splitter

you can put 3 pin fans in it, even tho it is meant for pwm... the 4th cable is just a pwm sense line.
it has a capacitor built in for stuborn fans that overdraw current @ start votlage... what i mentioned in statement 2.
and it uses a SATA power port to power the thing so you dont need to break out a 4pin standard molex if nothing is using it.

I'm sorry for so many posts but I must be clear before I make any purchase of a splitter. This link you posted is a PWM fan splitter....my fans are 3 pin non PWM so it is my understanding I will have no control over fan speed with this splitter. I will only be able to monitor RPM speed of a single fan. That is not my intention. Is that correct?
 

donfm

Senior member
Mar 9, 2003
677
0
71
You could get one of these, which come from many different mfgs and many different styles.
I'm sure you have already thought of these.

This one works with voltage controlled fans and will warn you if a temp gets too high or a fan quits.

It's not automatic, though.

http://www.thermaltake.com/Cooler/C...roller/C_00002777/Commander_F6_RGB/Design.htm

I can find plenty of non automatic 3 pin fan controllers but none automatic. I will just have to assume what I want to do is not possible with 3 pin voltage controlled fans. Thanks guys for trying to help....Over and out.
 

aigomorla

CPU, Cases&Cooling Mod PC Gaming Mod Elite Member
Super Moderator
Sep 28, 2005
21,087
3,598
126
I'm sorry for so many posts but I must be clear before I make any purchase of a splitter. This link you posted is a PWM fan splitter....my fans are 3 pin non PWM so it is my understanding I will have no control over fan speed with this splitter. I will only be able to monitor RPM speed of a single fan. That is not my intention. Is that correct?

Yes your correct.
You will not have fan speed control, because it is no longer tied with your motherboard and is tied directly to your PSU.

If you want a manual form of fan speed control you will need something called a fan controller.

https://www.amazon.com/Kingwin-Chan...id=1517341431&sr=8-10&keywords=fan+controller

something cheap like this will work but it fits in a 3.5inch bay, so you may need a bay converter.

I can find plenty of non automatic 3 pin fan controllers but none automatic. I will just have to assume what I want to do is not possible with 3 pin voltage controlled fans. Thanks guys for trying to help....Over and out.

You want it done automatic over software?
it will cost you..
https://www.amazon.com/dp/B00GPVGOOY/ref=psdc_3015422011_t1_B01M9FAFB0

Unless u can find one of these guys which are no longer made.
https://www.newegg.com/Product/Product.aspx?Item=N82E16811995075

That sunbeam had 1 line which went to PWM and would automatically control the fan speed from the reading on that pwm line.


Also that gigabyte board has at least 5 fan headers.
What do you need so many fan headers for?
What fans are you running on your system?
 
Last edited: