Thanks for the answer.
Do you get at least 30 MH/s? I can't go over -mclock 1890 MHz, and my hashrate stays under 29.50 MH/s.
If you're using just one card and using it as a display output for windows you may lose a few hashrates. Use the iGPU and the display output from the motherboard so you can fully use the GPU for mining.
I don't think is losing more than 0.5MH/s, but anyway, I use iGPU on all my rigs. This is my testing PC, where I am testing the OC before I set it in the rig, to minimize the downtimes.