Minig rig issue, plz help :)

[PrincessLittlePiddle]

Can tell you that it’s most likely your motherboard. Check out this thread for more information as the ASUS Z170 is notorious for this issue:

Are Z170 boards a lost cause?

You can run at least 5 GPUs on Z170 but it may require some BIOS setting changes. I had a lot of kernel panics, boot failures, etc until I enabled 64-bit PCI-e addressing, disabled USB3.1/thunderbolt and forced PCI-e Gen2 on the CPU links and PCI-e Gen1 on the chipset links. YMMV of course as each board is different.