Run gpuz and check gpu load in second tab, should be around zero when idle. And don't mind the jumping, it will do that because of anything you have open on your desktop.
Basically it should report zero every other moment.
You can use cpuz and realtemp to check cpu speed and temps, are those idling correctly?
If you open the ccc drivers and go to performance/amd overdrive you can enable that and leave everything at default. Maybe your card doesn't idle correctly so worth a try.
Does your card reach the correct speeds when running a game or benchmark?
Does the card behave the same in windows safe mode?
So if everything says your at zero activity for the gpu, it could be your cards bios is faulty or configured that way since it's in that where the powerstates are defined.
On a side note, some animation or video could be causing this, even when closed, maybe something that starts with windows and keeping the gpu in the wrong state?
Thanks Flow. CPU speed and temps are idling correctly. I'll try your suggestions tonight!