You can check the fan settings in the bios, and if needed set up a fan curve with low rpm's at low temps, that increases with temperature up to max rpm's.
It's straight forward enough.
So the auto option isn't good?
Auto option should be fine, and adjust on the fly, but you said yours was pegged at 1500 so maybe the auto feature is messed up. You could try a bios update to see if that helps, or as mentioned try the manual fan curve.