@yun999 -- I'm curious about how you use the 4k PSU bundles with open rigs.  It seems one PSU would power 4 or more rigs (at 6 cards each).  So when you have to take one rig down, what do you do?  Disconnect the 9 power cables going to the cards and risers?  Or are you rigs set up so you do maintenance in place?  I have to move mine to replace a card.  Right now the ATX PSU goes with it, so to do maintenance all I have to do is disconnect the 120v AC and the network cable... and its a unit.

I am liking the 4k PSU bundle, just not sure how to deal with it.  Or maybe I should build a massive open rig with multiple motherboards and GPUs and treat it all as one unit. LOL!.