My FirePro v4800 starts lowering it's performance output after ~2minutes of not using the computer. Framerate drops to 5 FPS and it's very annoying when watching videos because of having to sit with the mouse in your hand..
Edit: I found that the msdn.exe causes this, has nothing to do with AMD. I personally removed it with Malewarebytes AntiMalware, which is free, and this problem stopped happening!
Here is the link on msdn.exe:
10:16 AM by