Quick question: How did you get your fan xpert to start the Noctua P14s at so low speed? I've got a Maximus Impact and my fan xpert won't detect any lower startup speeds than apx 650 rpm..
On all asus motherboard i have tested, on the initial boot, the fans speed up to whatever the bios is setup to in the Fan Control, after windows loads then fanXpert2 should enter, so in essence fanXpert2 never starts up the fans from 0, he just recieves them from whatever the bios ran them through the booting process. Try to increase the speed of that header on the bios, to garantee you reach your 650rpms you need for the fan to start, so when it enters windows it should sustain the speed.
IIRC correctly, that test runs the fans from 100% (PWM) downwards
until they stop. In this case at 20%. So you could test to that speed, but probably not start them there. And then use BIOS & Windows to start at 50% and pull it down to 20% for idle.
I'm running Linux now, or I'd just try it on my 3770K Maximus IV Gene. Although, apparently the only true PWM connectors on ASUS boards are CPU_FAN and OPT_CPU.