I currently have a single rail PSU. I have been reading a lot lately about dual ans quad rail PSUs. My question, though, is how do you know which connector goes to which rail, do you have to have a multimeter? It can't be that difficult. Or, does is even matter which connector you use? I have seen the connectors for modular multi rail PSUs and they look a little easier to understand; especially the ones that have color coded cables for the PCIe, 4-pin Molex, etc.

I guess I am just confused by it all. I read the review on the Etasis 850W, and it really made me wonder how to figure out which connector goes to which rail as it is not modular. Can you guys help me out, break it down "Barney Style," please?

Open it up and follow the leads Or... open up the manual, there will be a page specifying where each wire goes to.

Normally though, there is one 12V rail for each PCI express connectors.

So the regular 4-pin molex connectors don't make a difference?

Those are connected to one of the 12V rails, check your manual

I'm not concerned about my current PSU, it is only a single 12v rail unit. I am just trying to understand the multiple rail PSUs. From what I am getting out of this post, there is a 12v rail on each PCIe connector, and I would assume that the 4-pin molex connectors each are connected to a different rail also. Or, in the case of dual rail, they may have several PCIe and 4-pin molex connected to each rail. That way you can distribute the power evenly among the devices so that one rail is not pushed too hard.