Asus Crosshair V Formula, Fan Speed Problems

[Jkirch]

This motherboard has 3 different types of fan connectors,
CPU_FAN, CHA_FAN, and OPT_FAN.

My problem is when I connect a case fan rated at 2500rpms I get:
CPU_FAN rpms = 2400
CHA_FAN rpms = 2000
OPT_Fan rpms = 600

They are all 4 pin connectors on the motherboard and the fans are 3 pin.
I have tried a couple different fans rated at the same rpms.
I have also tried every setting in the bios but nothing will change the rpms.

Are these different connectors made for different types of fans?
I would like to be able to use all of the connectors run them at full rpms.

Thank you for all your help.

 

[Woomack]

Depends from fan connector you have different options on this board. I don't remember exactly but optional fan connectors have less options and cpu is usually running a bit faster. When you turn off any fan options ( turn off q-fan in bios ) then it should work on max speed ( 90-100% depends from connector ) but really all is mixed up on this board.
I was using 3 and 4 pin 120/140mm fans and I could change speed on all of them just not all had the same speed, +/- 200 rpm even when I was using exactly the same fans but on other connector groups ( there are 2x cpu, 3x optional, 3x chassis ).
If you have problems in UEFI then try ASUS soft and change fan profiles there ( q-fan has to be enabled in UEFI ).

 

[Jkirch]

I have tried it with q-fan on and off, in the bios and the asus software, with the same results.
The only fan q-fan seems to control is the main cpu fan.
All the other fan connectors stay at the rpms mentioned above.

I can't find any information if the "EZ PLUG" would supply extra power for the fans or not. It's a 4 pin molex that supplies the board with extra power. From what I understand it only supplies the pcie ports, but I may be wrong.
Could I not be getting enough power to supply the fans?

 

[DolbyTrueHD]

Change the duty cycle in bios..or use the fan expert provided by Asus. Also make sure your fans are set up on DC(3pin) instead of PWM(4pin). Remember that when you introduce load on the CPU, the fans should kick in and due their job. Just because you have them set on turbo and/or full duty, don't mean they will spin at the full RPM. When you run something like prime95, they should spin up to their rated specs. Hope this helps!! Also your goal should be to run a quiet system, specially if you are gaming, that's what your specs look like.

Asus Formula V ROG
AMD FX-8120 Bulldozer (OC 4.5)
Corsair H100 Cooler (Cougar Fans Push/Pull Conf)
Kingston Hyper X Limited Black Edition 8GB
Corsair 2x 120GB SSD's Raid 0
Samsung 1.5TB Storage
2x XFX 6850's
OCZ 700 Watt PSU
Corsair 650D

 

[Jkirch]

I have tried all of the settings in the bios with prime95 running, including the duty cycle, with no effect on the fan rpms.

 

[DolbyTrueHD]

I would try a different fan, if there is no change and you're sure you've got the settings dialed in, then you need to rma your motherboard to let Asus correct the issue. Hope you get this squared away!!


Asus Formula V ROG
AMD FX-8120 Bulldozer (OC 4.5)
Corsair H100 Cooler (Cougar Fans Push/Pull Conf)
Kingston Hyper X Limited Black Edition 8GB
Corsair 2x 120GB SSD's Raid 0
Samsung 1.5TB Storage
2x XFX 6850's
OCZ 700 Watt PSU
Corsair 650D