Right, so as you all know the Crimson Drivers are TERRIBLE!
I'm running a 7950DD 3GB
So the problem is the driver itself I think. Upon installing 15.12 I couldn't overclock as it would 'stick'. The driver would start to see the new OC speeds as the minimum and constantly run at that.
If I was gaming 24/7 this wouldn't bug me as much, but I'm not. Idle temps soar from 38celsius to around 70celcius which can't be healthy for any card to constantly run at.
The reason I pinpoint the driver and not the new crimson software is because I installed 15.11 CCC (had it still knocking about from a previous update) and then installed the newest driver but without the new Crimson software. So then I've got CCC running as my software and 15.12 driver. Same bug appears.
The only way to cure it is the run cleanup and re-install. Had a gander at my dads PC, he's running 15.12 but without OC (running MSi R7 370 4GB). The clocks raise up to their default 'max' factory speeds and then return to 300/150 when idle. As soon as the clocks are altered all hell breaks loose and the driver forgets how to work.
Both running windows 10-64.
I'll be sticking with 15.11 CCC until the issue is sorted but I thought I would share my experience with the bug.
Come on AMD, don't make me change my mind about upgrading to an R9 390x!!!!