The mobo needs none of those red 8 pin sockets. It uses the enormous socket labeled MB,and the black 8 pin one labeled cpu1.
Hehe.... Lots of confusion !!! Leave the 24pin socket
You are referring to the EVGA PSU picture. In that, yes I agree :
CPU1 -> gets connected to the CPU connection on the Mobo
CPU2 -> gets used for the additional 4pin connection in the Asus RVE
Now for 2 GTX 1080s with 2 power connectors each (8pin + additional 6pin). The question is : how many of those red connectors will be used ?
1) 4 : one cable for each power connection to the GTX 1080
2) 2 : one cable has two connectors at the other end
From a Corsair perspective :
There are 6 8pin sockets on the PSU (I guess they can be used interchangeably for CPU as well as PCI-E - that's how they are marked). So,
if the answer to the above question is (1), it would mean that I need 2 + 4 8pin sockets on the PSU. And only the RM1000x has it.
if the answer is (2), 2 +2 8pin connectors are enough and I can move to a lower wattage PSU.
Now, is the question not clear from the time I have been asking it ?

I am really very confused.

I believe that I cannot put forward the question in any more simple terms
