Question about CPU_OPT fan header.

[Mr Tosti]

Hey guys, 

 

I have a question that I can not seem to find the answer to.

Since I want to watercool my system but also want to control my 3-pin fans I would like to hook them up to the CPU_FAN header. This header can provide 1A  and 12 watts, now this would be enough for roughly 12 fans (would like to run 8 per header)

 

But what I do not know, and can't find any information on is if the CPU_OPT has these same power specs? Does it also support 1A, 12W? Or is this shared? So, is it possible to run 24 fans on these 2 headers alone or do they share the power and thus, can only still run 12 fans with both headers?

 

Thanks in advance!

[ZetZet]

What motherboard.

[Mr Tosti]

Asus Z-97 Pro. I looked up the max power of CPU_FAN in the manual which is 1A (12Watt), only I can not find anything about the CPU_OPT

[ChaseB]

Asus Z-97 Pro. I looked up the max power of CPU_FAN in the manual which is 1A (12Watt), only I can not find anything about the CPU_OPT

It run at max power. I don't know specs but I know you can't control that port (cause it runs on full). With it running at 100%, it should run 8 fans easy

[Mr Tosti]

It run at max power. I don't know specs but I know you can't control that port (cause it runs on full). With it running at 100%, it should run 8 fans easy

Actually I can control the fan, in fact I currently am via Fan Xpert. Only what I wanted to know is, are the CPU_FAN and the CPU_OPT connected in the same electrical circuit or are they separate? E.G. can they both deliver 12 Watt separately? Or do they share the 12 Watt? I can't find anything in my manual and I really want to know since I want to go push pull and be able to control 2 sets of 8 fans.

[ChaseB]

Actually I can control the fan, in fact I currently am via Fan Xpert. Only what I wanted to know is, are the CPU_FAN and the CPU_OPT connected in the same electrical circuit or are they separate? E.G. can they both deliver 12 Watt separately? Or do they share the 12 Watt? I can't find anything in my manual and I really want to know since I want to go push pull and be able to control 2 sets of 8 fans.

I have the model down and I cant control that port. That is cool that you can. That port is meant to plug in water pumps so you can run them at full power. The OPT and CPU header are separate and can run what you want to do

[runit3]

1A should be per header (all headers). I know they are rated that way for both my X99 and Z97, I called ASUS and asked.

[ThomasD]

You need to look at the specific power draw for each fan you plan to connect to each header, add them up and be sure it does not exceed the stated 1 amp limit.

 

As an example Corsair AF140 fans are rated at 0.1 amp each.  Conceivably you could run ten of those, at max speed, off each header.  Although I'd recommend no more than eight as a simple safety margin (manufacturer ratings are usually somewhere in the +/- 10-20% range.)  

 

But, if you had another type of fan, and they were rated at 0.15 amp each then you could only safely run six of them off one header, five to be totally safe.

[Mr Tosti]

Thanks for the help guys! I know enough now