Solved!
I've update drivers to 17.5.1 and now it's mining almost same only about 30h/s lower, so I guess there is some HW problem still, but it was main SW problem... bad drivers install maybe?
It seems like power problem of the PCIE... MSI Afterburner showing few watts lower power.
I think I will still buy new HW.
Any suggestions?
I was looking on this
Gigabyte H270I've read that MSI B250 only support 4 gpu. Is H270 support 6 PCIE devices?
Thank you guys for support. I really appreciate it.
Edit: 1 restart and I'm back in low hasrates... it makes no sense!
Edit2: another restart and mining fast again, it's like lottery!