P.S
In which order your cards are plugged? Lattes PCI-E is empty, right?
Im using win10 anniversary with 8gb ram and m2 ssd (64- barely fits, so lately 128)
Normally I do leave next to the right from x16 slot unoccupied, but I noticed no difference in order and number of connected raisers/cards WHATSOEVER, despite some talks here
Disclaimer: I'm using AMD predominantly and maybe there're some issues with Nvidia after all, since I tried to setup 9x1060 paired with two Vegas FE, but it just refused, while 8*1060 + 2*FEs works just fine.