yeah ,my hashrate is a bit low too , i believe .
since my GPU load is low and very variable.

it is supose to be higher i think, and GPU utilization needs to stay away .
but it does NOT and kicks in , then my clocks go lower

i think if  ccminer could do desktop interactive disabled i get better performance , but i dunno for sure .  
i am not the expert.
but on cudaminer , it makes a world of difference for my GTX 780 lightning