For those waiting on the info for the MSI Z170A M5 Gaming board and 7x GPU support I finally have it working on both of my boards.

1) Make sure you're running the latest BIOS!
2) Enable 4G
3) Set PCIe support to "Auto" - DO NOT MANUALLY SET TO GEN1. THIS CAUSES MAJOR ISSUES
4) Enable onboard graphics startup as first! I believe this is changing "PEG" to "IGD" or something in the Advanced BIOS
5) Plug your monitor into the ONBOARD graphics
6) Use either simpleminer-RX-v1093-4.11.rc8-16.60-enableexe0ANDips0.imgc or simpleminer-RX-v1093-4.11.rc8-16.60-enablerc60.imgc (sorry, I don't remember which I used!)

My 14x GPUs have been stable all night long!