Try the newest AMD drivers (I think 17.3.4 or something like that) and then use them using the Pixel Patcher (Google for it). I am using the newest drivers patched and they are hashing well. Are you sure you used a modded ROM for the memory type in your card. The memory used in the cards can change from run to run. So a mod for your card for one memory type might not work properly or has well if you have another memory type in your card. Check out youtube videos from cryptomined and others. They have lots of good information about modding, putting together rigs, etc. It also might be an issue with the BIOS on your motherboard. Some just do mine well. Make sure your motherboard BIOS is the latest available for your board.