Setting Chassis Fan Control below 60%

[pam007]

I like my Maximus VIII Hero Z170 so much I had to replace my MSI X99 motherboard with a Strix X99 motherboard in my second system.

But there's one thing I don't understand. How come ASUS motherboards don't allow manual DC Chassis Q-Fan Control to be set below 60%?

I notice this was also true with the Hero Z170, but I was able to work around this in the advanced monitor settings (and as long as I didn't ever go back and change anything in Q-Fan Control). Strix X99 won't even allow the work around.

Is this a purposeful safe guard/limitation ASUS designs into the UEFI?

My second system specs:
ASUS Strix X99 Gaming BIOS: 0401
Intel i7-5930K CPU
EK Supremacy EVO waterblock CPU cooler
GSkill 4x4GB DDR4-PC3200 memory
EVGA GTX 980 ti Classified graphics card
EVGA G2 850 watts PSU
Thermaltake Core-X9 case

[Onimax]

Hi pam007, did you already perform the fan tuning? (It's located in the AI Suite under Fan Expert -> "Fan Tuning" - and can also be accessed in the EFI under "Monitor" in advanced view)
That way the mainboard checks at what PWM strength/DC voltage your fans start to spin.

Generelly speaking DC controlling your fan is not so fine grained as controlling your fan via PWM, so if you have that option I'd recommend to give it a shot.
If you really want very low rpms with fans that are able to operate at 2-3k rpm try to find some extended range fans like the Noctua PPC Industrial 2000 or the new Corsair ML120/140 Pro - those are actually able to spin at ~300rpm.

Hope that helps.

[pam007]

That makes sense now. I forgot about some fans not having the ability to start spinning at lower voltages.

I use three 120mm x 38mm Delta high static pressure/high RPM fans that are very efficient at pushing air through an EK-CoolStream XE 360 radiator. They can do this even at low RPM. They're DC (3-pin) fans that can start spinning at extremely low voltages, at ~10%.

I'm sorry, I haven't installed the OS so I can't use AI Suite yet. The first thing I do is perform fan tweaks in the UEFI because three 3000 RPM fans blowing air full tilt through a high fin, 60mm thick radiator scares the wits out of my cat, lol.

I tried changing "min duty cycle (%)" under "Monitor" in the advanced EFI to a value below 60, but every time I do so, it immediately switches back to 60. As mentioned, the Hero Z170 allowed me to do this, but the X99 Strix does not.

It looks like I'll just have to wait until after I install Windows then.

Thanks for your help.