I have the 10.4's and it takes around 8-9 seconds to load. I would suggest you look in your ATI folder to make sure you do not have more than one driver installed. If you are using "Steam" it most likely that you have more than one driver installed since Steam auto updates the drivers. If this is not the case then try a fresh driver install and use driver-sweeper to remove everything related to ATI/AMD/CCC.
1. Download the driver and save to desktop.
2. Remove the existing driver via the control panel/ATI Catalyst Install Manager.
3. Run driver-sweeper and remove anything related to ATI/AMD/CCC and reboot.
4. Run driver sweeper again, if all files have been removed proceed to installing the new driver, reboot, done.