PWM not working with splitter

[amiltonpueljr]

Hi guys,

I bought a splitter from gelid (http://www.gelidsolutions.com/products/index.php?lid=2&cid=11&id=63) to try hooking up 2 fans (http://www.gelidsolutions.com/products/index.php?lid=1&cid=2&id=57) on the same sysfan.
Well, it doesn't work. If I connect the fans through the splitter, fans run at top speed and make a lot of noise.
If I connect fan directly to motherboard, PWM works great, but there'll be 1 fan in the drawer and that's not money well spent.
I tried the splitter on my brother's computer, and it worked.

U guys have any idea what's wrong with it?
My system: Phenom II X4 B55 Black Edition/ Gigabyte 880GMA-UD2H V2.0/ 2x2GB DDR3 1600mhz Kingston/ Sapphire 5670 512MB GDDR5/ HD SATA II Seagate 1500GB/ Fatal1ty 550W

[autotech]

Are you connecting it to the cpu fan or the bottom fan header?

[amiltonpueljr]

I tried both of them, same results.

[Dark Mantis]

Hi

Have you got the fan output set correctly in the BIOS ? Even though they are PWM fan headers there are different options for setting them.

[amiltonpueljr]

I figured out what the problem was, here's the deal.
My motherboard can control the speed of fans by two means. First of all PWM, or Voltage control.
CPU_header can work on both ways, and it was set as AUTO at the SETUP. SYS_header can only work with Voltage control.
The thing is, when there's only 1 fan connected to CPU_header, it would control fan speed on both ways, but if using voltage control and the splitter it wouldn't work for obvious reasons.
When I setted CPU_header to PWM, the splitter worked just fine. Not only that, 4 pins doesn't necessarily mean it's PWM, and if not PWM splitter won't work (like my case, splitter won't work on SYS_header 'cause it's not PWM controlled).
Now I've got splitter on CPU_header with 4 fans and another fan on SYS_header and it's all good

One question remains, why the forth pin on SYS_header if not PWM?
From manual:
CPU_FAN: Pin1=GND, Pin2=+12V/Speed Control, Pin3=Sense, Pin4=Speed Control
SYS_FAN: Pin1=GND, Pin2=+12V/Speed Control, Pin3=Sense, Pin4=Reserve

They could've at least wrote:
CPU_FAN: Pin1=GND, Pin2=+12V/Speed Control(Voltage Control), Pin3=Sense, Pin4=Speed Control(PWM)
SYS_FAN: Pin1=GND, Pin2=+12V/Speed Control(Voltage Control), Pin3=Sense, Pin4=Reserve

[autotech]

While PWM fan controllers are very common in today’s PC industry and available on most mainboards, there is often only one or two such PWM headers, reserved for the CPU and or the chipset fans. One way this excellent noise reduction idea can be extended to the numerous case fans inside a typical PC is by utilizing a GELID PWM splitter. I figured your cpu fan header was pwm, I was sure that the lower fan header wasnt as that board doesnt have a northbridge fan on it. I am glad you got it sorted.

[Dark Mantis]

The only thing I would council caution on is that if you have more than one fan attached to a motherboard header it is obviously increasing the load and these headers have been known to burn out. I understand that the maximum current is 1 amp per header so make sure that you keep under that limit.

[amiltonpueljr]

The only thing I would council caution on is that if you have more than one fan attached to a motherboard header it is obviously increasing the load and these headers have been known to burn out. I understand that the maximum current is 1 amp per header so make sure that you keep under that limit.

Sure, but splitter gets power from PSU, so no problem there.
1 amp per header? didn't know that, good to know