i drained my system and installed 2nd lower card in the first slot and nothing ...have you tested all the pci-e power ports on the psu with the with both sets of cards? I'm not really sure how you are figuring this stuff out etc.
I'm not sure. I just viewed a bunch of unboxings and they all had 6+2 x 2 on each modular cable, so maybe I'm wrong, or I may have had a CS750M instead.The tech specs on corsair website say this PSU has 4 PCIE connectors not 2. After all is a 750W. I had a 650W that was having 4, so it would have been a bit lame for Corsair to showcase only 2, on quite a high powered PSU on single rail design.