glad that u solved your issue. i have 1600w psu and looks like its random when i get all gpus online, changing pci ports for risers seems to help boot …allso every now and then, so do you mean that some of the gpus should be comf to gen 1 and othes to gen 2…allso " use the second one" do you mean ports, white and black inputs, i know that white one have lover amp output, but anyways sometimes my setup work best, boots up wit all gpus, when majority of gpus are connected to these low amp ports. edit. ihave tried everything i can come up with, i have another rig, same mb that is running stable with 8gpus, dont have space for more now and i belive cant add more due psu limitation, 1350w.That one is drawing 1050w from the wall. This 2. rig with issus run fine fith 7gpu´s, sometimes it boots up with 8…i belive i need to wait for 2.psu adapter to make sure that its not the lack of power etc. I have changer risers from non working to working one, and it seems that its not about those. getting really frustrated on this issue…i belive that so is my wife too… im spending all my waking hours trying to make this “pos” to mine with at least 8 gpu´s, just sold 2 cards because i couldn´t use them, well ill try to found new ones when and if i can get this up and running, nice “hobby”