So I've been trying to mine Ethereum with a RX570 8GB Nitro+(Hynix) and for some odd reason I can't get it to mine more than 20mh/s

My Spec:

Windows 7 Home Premium
Claymore 9.8
Crimson Relive (lastest one) + leaked DAG fix
BIOS mod (strap 1750 to 2250)

I clocked my GPU to 1300 and mem to 2100 (Anything over than that gives me a lot of errors on hwinfo).

How are people able to get 30 mh/s yet this card is only able to get 20 mh/s?

Any help?

Thanks!