Can Anyone help me ?

i Have this Problem with algo Phi2   

When i had drivers 399.24  with 6 1080ti's i was hitting 68 MH/s

Now That i have download  latest Driver 416.34  i'm at 57 MH/s

That is a Big lose for me.
i dont want to swith back to 399.24 because of Cuda 10 ( Would have to make other Changes )
PLS Help .

Thx