The gtx 1070 is my main display.
If you have onboard GPU i would swap to that - helped my 570 a fair amount.
I was getting 29MH then 8MH then 29MH then 8MH so effectively every other "Hash report" from claymore was loosing 2/3 Hash on the card.
Swapped to display as IGPU and now solid 29MH.