Go into the options/advanced screen and use the pull downs to select "something" on the third or fourth tab. Then you have access to speeds. Sorry I can't remember what it was. Don't really want to install it again to find out...
Word of caution: SpeedFan is iffy with some sytems. Like my decent HP a1330e. Weird things started to happen...random 100% all fans, could not alter this speed until restart etc.
My copy of speedfan spins my fans up and down just fine. It even turns two of them off when not needed.
First you need to calibrate it by setting the offsets for the fan rpm and temperature sensors. Once you have it reading the sensors correctly,
You need to associate a fan with a temperatuire sensor, then in the "speeds" section, set the max and min fan rpm. Lastly, on the main screen, click "Automatic Fan Control"