Okey...

let's say I'm trying to build rig with 6x RX480, ASRock BTC Pro Rev2 etc...

now for this I could use let say 1x 1300W PSU or 2x 700W PSU.

Now my question is what are the risks of running rigs with 2 PSUs? (not wiring and stuff, I'm asking about failure risks)

I mean what would happen if just one of PSUs would die while there are 6 GPUs on full load on that system?

Fried mobo? Fried GPUs?