Dear virtual friends.... I bought an ASUS gamimg system last year, prepared by a 3rd party (case, motherboard, chip-set, ROG RYUO 240, etc - they did the installation). Then it began the nightmare with Armoury Crate and I tried different scenarios - installing-uninstalling, etc.
The issue comes from the FAN cables connectivity to the mother. You have to read carefully the motherboard booklet where there are indicated all the FANs sockets (4 pins/PWM). Then identify the cables which come from the 2 FANS above the case and insert them in 2 of these sockets - I recommend FAN 2 or FAN 3.
Then you can adjust the speed, FINALLY, from BIOS and don't need any other applications like Armoury Crate, etc.
The initial installation was with the cables which come out from the ROG RYUO 240 which makes them having a constant, nonadjustable, high speed (not maximum, as far as I heard) but still very annoying.
So open the case and redo the connections of the 2 FANs! That's all.
I hope this will help everybody here!
Cheers