The fan control is on the overdrive page thingy...or whatever the overclocking page is called. You have to unlock the controls.
Interestingly, check boxes to enable the fan control and/or the overclocking are separate...but even if you don't increase the numbers and want to run stock the overclocking box has to be enabled for the fan control to have any effect. This is despite the fact that the fan controls are not greyed out with the overclocking option off...you can still set the fan options (they just don't do anything.) ymmv