When you tested each GPU, did you test them individually or with the others plugged in. Or one by one. I'll give that a try both ways in just a moment. So should I just count on only using x5 with a 1600w? If so thats fine for now.

Any ideas how I could find the 12.6 trick for windows 8? I had windows 8 with 13.1 earlier and device manger saw all 5 of them that were plugged in at the time just fine. However, when cgminer started I would see all the hash rates jump up where there suppose to be, but then the screen would either freeze or go blank and I would loose all control, it was like the driver was crashing.

Not having to short any pcie slots would be nice, I had to short one of the 1x on my gigabyte board. It has no problem though seeing all 6 in ubuntu or xubuntu, I just cant run cgminer with a thread concurrency above 1792 or all the cards but one report as off, on the flip side if i run at 1792 they all hash at 150 or so, but i get 10 HW error a second a card so thats issue as well.

I'd prefer to stick with windows 7/8 so that I can utilze afterburner to turn down the voltage, though I suppose a bios flash is always an option?