+1 for the PSU part of the topic above. I couldn't agree more. However, I would like to add following: You system is only as good as weakest link in it. Now when it comes to mining rig you could think that is not so important but better to be safe then sorry.
I was fortunate to bump into my rig one night while passing trough basement. One line from power cable on one of the PCIE risers has apparently disconnected itself from connector and found itself next to metal (I think aluminum) frame of my rig. When I bumped it in the night there was sparks everywhere. After closer inspection I wound the wire and it already burned trough few milometers of aluminum. The rig was working normally and I was not aware of any problems and it could have burned everything down
I was fortunate to bump into my rig one night while passing trough basement. One line from power cable on one of the PCIE risers has apparently disconnected itself from connector and found itself next to metal (I think aluminum) frame of my rig. When I bumped it in the night there was sparks everywhere. After closer inspection I wound the wire and it already burned trough few milometers of aluminum. The rig was working normally and I was not aware of any problems and it could have burned everything down