SpeedFan is popular, however it hasn't been updated for a number of years, and I ran into problems with SpeedFan as it was not able to read the sensor chip on my current motherboard.
If the fans are connected to your PSU alone, I don't see how it would be possible to control them using softare.
If the other fans are actually connected to the motherboard or a fan controller, but you are just not able to control them, I'll recommend trying
Argus Monitor
It is free for 30 days with full acces to all features. It does require some setting up, to get the most out of it. You will quickly be able to see if it works though.
Personally I find it very usefull and don't really have much negatives to mention
You could try to install it, and see if that program is able to read the sensor chip on your motherbord, if it is less than 4 years old, it could be a possible solution.
But again, if the fans are not actually connected to the motherboard, I don't believe you will be able to use software control, although I can't definately rule it out