I'm a newbee.. Please pardon if I've missed any critical detail in this question.
I have three ASUS Z270 AR motherboards and 21 Asus dual RX 580 GPUs. Out of these, one rig with 7 GPUs work really well. I'm having problems with the other two. Whenever I connect more than one GPU to any of the other two motherboards, only one card hashes while the other does 0 hashing and in a minute, the whole Windows 10 desktop freezes and i have to reboot. I even tried with ETHOS it has the same issue.
Ive done the bios mods on the motherboard for the pch gen2. The computer works just fine and shows all the 7 cards in the device manager correctly. Only when i start the claymore dual miner, that's when it crashes in a minute.
When i try to connect one single GPU - one by one on every PCI-E slot, all the slots works just fine independently they hash at 27mhs.
When i try to connect one GPU at a time to its appropriate PCI-E slot, every GPU hashes just fine at 24 to 27 mhs.
I'm using a 450W gold power supply for each rig along with two HP DPS1200 power supplies.
Any guidance you could provide on how to fix/troubleshoot would be of great help.