Chassis Fan Ratio
Possible values of an option:
From [60 %] to [90 %], [Auto]
[11/16], [12/16], [13/16], [14/16], [15/16]
The option description:
At switched on intellectual control gives the chance to specify speed of additional fans of the system unit (in percentage of maximum or in the form of a ratio) at low temperature in the case. In most cases optimal value will be [Auto] if you want to achieve noise low level, select minimum speed.