Guys I am having issues connecting 5+ gpus.

I have their mobo, 128 ssd, 8 gb ram and their ATX PSU. For some reason windows is giving me a freaking hard time getting more than 4 GPUS STABLE, 5 gpus and windows gets choppy, 6 and it wont even load. Suggestions?
 
I have been installing one by one, turning the rig on, off, next gpu, on, off, and does not work. I change them slots, connectors, not sure what is going on here. any ideas would be appreciated. THANKS.!