Question When mining with 2 cards it's slower than with 1

[Kacpersk]

Hello,

Specs:
ASRock z170 Pro4s
I5 6500
8gb Corsair ram
Be quite pure power 10 550w

When run my GTX 1070 alone it gets about 26mh/s and my GTX 1060 6gb gets around 20 mh/s, but when I run both of them in the same system lolminer for some reason halves both cards resulting in my GTX1070 getting 15mh/s and my GTX 1060 10Mhs for a combined total off 25mh/s. Does anyone know what causes this or how to fix how to fix this?
I've already tried Bios update, installing chipset drivers, uninstalling video drivers and reinstalling them,

any help would be much appreciated

 

[sizzling]

Are any cpu cores hitting 100% usage?

 

[Kacpersk]

Are any cpu cores hitting 100% usage?

From what I can remember no but I would have to double check in the morning,