Judging by the volume of fan header related content across the net, it's clear that there exists lots of confusion around the subject of how to best utilise the fan headers on the ASUS motherboards.
I've just built my own machine.
I have an ASUS P8Z77-V mobo, into which I've slotted an Intel i7-3770K. I took some advice and got an Antec H20 620 Water cooler for the CPU.
The case I got is a cooler master and has space for two side fans, a top fan, a back and a front fan. The back fan is now the fan that the Kulher radiator sits on. I've got fans for all of the other spaces.
On this motherboard there are 5 fan headers
All the fans I have to connect are 3 pin fans including the one supplied by Antec for the water cooled CPU action. As any users of thse board know fan headers are 4 pin.
The mobo comes with Fan Xpert 2.
The concensus seems to be that plugging anything into the CPU_FAN header is uselss unless it is a 4 pin connector.
Now rightly or wrongly I've plugged the water cooler fan into the CPU_FAN header
One of the chassis fans plugged into the CPU_OPT
The other three chassis fans plugged into the actual chassis fan headers 1, 2 & 3
If I run Fan Xpert 2 and Auto Fan Tuning, it comes up with only four fans. The CPU fan is greyed out at the top. Underneath it shows a front a top and a side fan.
If I click OK from that screen I see
CPU fan - 1925rpm (displayed in blue)
CPU Optional (greyed out) - 1489rpm
Front fan - varying between 1080 / 1254 / 554 rpm (displayed in yellow, now back to blue)
Side fan (greyed out) - 0 rpm
Top fan - 0 rpm (displayed in yellow)
I can be rather dense sometimes, and while I appreciate the principles of RTFM, I'm still finding how best to make sure the machine runs safely, by connecting the fan headers correctly.
What I'm struggling with is
Not knowing which CPU header relates to what Fan Xpert calls them, CHA_FAN1, 2 or 3. grrr
Do people run Fan Xpert with all the fans out of the box so they know which is which?
The viability of the Antec Kuhler H20 620 plugged into the CPU_FAN header. Whether I should just discard it and use the 4 pin air cooled fan supplied with the processor?
Whether I can double my two side fans up with a splitter so I can run them from one header (they are both 0.37 amp fans at 12v which means I wouldn't have to use the CPU_OPT fan header or the CPU_FAN header (BIOS complained before when I didn't have anything plugged in there before).
I would welcome any input on this, however obvious what I'm missing is. If anyone says, the power of cognitive thought, it'll get a laugh this end.
I made an executive decision. For better or worse, I've removed the Antec Kuhler H20 620 and plugged in the fan that came with the processor, a 4 pin that I've plugged into CPU_FAN. I've driven the front and back fans directly from the power supply and I've connected the top fan and the two side fans to the CHA chassis fan headers. It just feels better having a 4 pin fan plugged into the CPU_FAN and not using the CPU_OPT at all.
I guess I'll see how the temperatures and noise is with this solution. I can always change it I guess.