OK after a few thousand combinations in BIOS, lots of reboots, crashes and Bluescreens due to "Driver stuck in Thread (or so)" I believe I finally have it running stable for more than 30 minutes:

BUT.. I have three cards .. Yet it only displays Fan and temp for card 0 .. Shouldn't it display for all cards ?
PS: And no, Card #4 is still not working, as soon as I plug it in the mobo disables the SATA adapter.. What a PITA .. Never buy a ASRock Gaming Z170 K6 Board for a rig... I'm still trying to get that running