stock bios, I can't remember the memory brand msi, Z170a Sli and Asus Gamer Extreme (I think)  are the only two I have tried on so far, was thinking about swaping around more to see if problem persists, but dont want to suffer down time from mining with the current boom    I will post more details, but I have tried a lot of things without success so far.  My problem with windows is that it wont recognize more than 4 cards, or I get an error in device manager saying there aren't enough resources.  With simple miner, which I understand to be unbuntu, it will find the cards as long as above 4g is enabled.  With the 4 cards it would dual mine DCR and ETH at the expected stock hashrate  21-22 eth.   I will update with more specifics as I continue experimenting.  I am trying to learn linux and will be trying to install dual boot systems on my rigs tomorrow.