Case fan wiring mods. Straightforward?

  frybluff 17:43 PM 23 Jul 12

This is probably one of those very silly questions, once you know, but as a first time builder....

If a case has fan speed control, and mobo has case fan control, presumably you can only use one, or other, presumably the mobo. If, then, the fans are three pin and the mobo fan plugs are four pin, is it relatively simple, just re-directing the cables, and using some sort of 3 to 4 pin adapter, or is it a bit more complicated than that? Mobo instructions just say WHERE to put FOUR pin plugs.

  KRONOS the First 18:35 PM 23 Jul 12

The three pin fan connectors will fit onto the motherboard headers very easily as you will notice that the headers have a plastic upright lug which slides between two ridges on the fan connectors.

  KRONOS the First 18:39 PM 23 Jul 12

Sorry answering this question on the tablet,not used to it yet.You can put three pin connect ions into 4 pin headers hence the plastic lug. There will not be to many 4 pin headers on you mobo I would not have thought.

What is your mobo?

  frybluff 19:58 PM 23 Jul 12

4 No 4 pin chassis fan connectors (plus CPU cooling) - Asus P8z77-V PRO.

Not yet got case, but checking specs and noted different fan pin count, on some, and thought it wise to check it wouldn't be issue. Many thanks.

  KRONOS the First 08:36 AM 24 Jul 12

Just had a look at your mobo manual and you are quite correct you have 4 x 4Pin headers which as you will see do have the plastic upright which will slide between the ridges on a 3pin connector.

Also the great thing about an Asus board is that it comes with a Q connector that makes wiring a case PW.HDD LED, reset etc. A breeze. Wiring cases has always been a bit of a pain for me.

  retep888™ 10:51 AM 24 Jul 12

If the fans have 3 pins only then they're not PWM supported, you can connect them to a controller & ± speed thru' undervolting.


Change all the case fans to these PWM fans click here

  frybluff 07:46 AM 25 Jul 12

Thanks guys. Please forgive my ignorance, but, as it's first self build, I have no past experience to compare with.

Are we saying, up to four fans can be POWERED directly from mobo, but if I want mobo to provide tailored speed control, fans have to be changed (or get a case with 4 pin fans).

Is the "normal" way to wire all fans to one central case control, and either wire THAT from mobo, or have some seperate speed contol, based on case air temperature (I presume mobo does it based on a combination of CPU & GPU loads)?

  KRONOS the First 08:34 AM 25 Jul 12

You can power a more than four fans by using a splitter by the way.

I am using this,Aerocool but I have used others, this was a nice one. Kaze

But no any fan be it 3 or 4 pin can be controlled or not or you can just plug your fans directly into your mobo and leave it at that. It really depends on your case, how good you are at cable management as having cables all over the place can restrict airflow. Which is most important, you are looking for a good amount of air entering from the front and exhausting out of the back/top.

  frybluff 12:40 PM 25 Jul 12

Appreciate that what I NEED is adequate vent, to keep case reasonably cool, when at full load. Of course, it's then nice if fans throttle back, when not required, to reduce noise. If I can acheive that by plugging fans straight into mobo, setting up once, and then leave mobo to manage them, that's great. What I want to avoid, if at all possible, is having to have to "shuffle" things, to an extent that may be beyond my abilities.

  KRONOS the First 13:21 PM 25 Jul 12

This I think explains what you need to know. wiki

  frybluff 13:58 PM 25 Jul 12


Thanks for that, looks like helful article. I shall have a good read.


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