I have a Sapphire R9 270x and i'm using the lasted updated of catalyst. Yesterday i tried to improve the performance in one game so i increase the clock frecuenc, etc. In order to avoid hight temperatures, i increased the fan speed. When i iniciated the game this things change, but after quit out the game the fan speed still was too hight. I turned off the computer and turned on, but the fan speed was too hight.
Go into the Radeon settings / gaming / global settings / overdrive and use the reset option.