Hashrates SLI 980 GTX

Hey first at all im very new to all of this... i just looked up on it and started it. I took the advices and pool from etherminer.org.
My Rig
Intel i7 4970k
2x 980 GTX EVGA Superclocked
16GB DDR4 Ram
1200W Supply

So my question is, when i start the .bat the cmd tells me something about a rate from 34 MH/s to 45 MH/s
How does it come when i check my Miner adress on ethermine.org it says Hashrate 8.0 MH/s

THX for help