Cant change my sys fan RPM

[Dbehemoth]

Hello, Im having an issue with my top chasis fan, i cant change the fan speed in speedfan, it does show that the fan is there and it shows me that the rpms are at 1900 but in the advance settings there is no option for fan #4 to change it to software controlled or anything, please help is there a program that is easy enough to just have a slider for rpms or something, the fan is connected in the mobo with a 3 pin conection, sry if my english sucks xD

 

[CDdude55]

If Speedfan can in fact change system fan RPM then it might be only enabled if the fans have PWM control, which allows fans to adjust there speed based on what the machine is doing. Fans that are capable of PWM control fit into a 4 pin fan header while a 3 pin fan header can only provide the standard 12v.