CPU_OPT Fan Header

[ShivP]

Hi,

I have 4x 4-pin Enermax Fans but only have 3x 4-pin headers and 1x 3-pin header on my motherboard. I want to use all 4 fans, but can't right now. However, I do have a CPU_OPT header next to the CPU_FAN header which I could use. Is this safe to use or will I have to fork out the ~£5 for a PWM Y-Cable? Will the 3-pin motherboard header be okay to use?

Cheers

 

[pastymuncher]

I believe it's for people who have dual fan cpu coolers so should work although it will run at the cpu fan speed.

 

[ShivP]

Well I got a cable like this; http://www.overclockers.co.uk/showproduct.php?prodid=CB-031-AK plugged into one of my 4-pin headers, with two fans connected into it and the molex connected, and it doesn't change speeds anymore I think the 4-pin header's aren't actually PWM?

 

[setter]

On most boards only the CPU and opt cpu fan headers are PWM. Opt cpu fan mirrors the CPU fan. My board in sig has all four pin headers but only those two are PWM. Manufacturers forget to say this a lot unfortunately.

 

[ShivP]

Goddamnit, thought so. How can I get all of these fans to work via PWM as I want to control them via SpeedFan? And how is SpeedFan controlling those other fans which are in the 4-pin headers?

 

[setter]

Try the 3 fan splitter on the CPU opt fan header. I don't use soeedfan myself, but bios profile or Asus fan xpert allowed me to control fans on that header using that cable. Are all your fans PWM models?

 

[ShivP]

Yes I believe they are PWM, weird they are in the CPU OPT fan header now and still I can't control them, I am using the black cable...

 

[ShivP]

Think I might have to buy a couple of these 4-pin Y cable things... Without external power or anything

 

[ShivP]

Bought two Y-Cables, hopefully they work.