R9 390 core clock stuck at 300Mhz

Hi,

 

I have had my R9 390 for a little while now. I am not great at graphic etc but my graphics card will not move from 300Mhz clock speed meaning I am getting awful performance.

 

I have not made any changes that I am aware of and have even done a clean windows install, cleaned, cleared and reseated my entire system to ensure no loose connections etc.

 

Any idea what this could be?