The wrong is strong in you my friend.
1)Wrong section of the board. Go to sabertooth.
2)There is an edit button. Doubleposting/pushing is rude
3)And you dont need a power supply as you have no cpu and other hardware. The gpu alone wont work, so no need for psu either..
But let my read my coffeecup : There is a mysterious value called TDP (or Watt) for each component.. ALso my cup tells my you can add them together to get an estimate of power consumption. The spirit also tells me you should add a couple of watts to be on the safe side
Quick check(eveything with small overclock margin)
CPU: 200W
GPU: 350W
other hardware 100W
Reserve: 50W
=> 650W good quality, Bequiet,Corsair,Seasonic.
(800-1000W) if you use a cheap china no name psu
4)As they are not the same cards you cant sli them. keep the ti, sell the 780. or sell both and get a 970/980. Who the hell would by a 780ti right now? hope you can give them back in time..
===========
About your main problem:
If slot 1 doesnt work and slot 2 works the problem is more or less clear: Your slot is broken. Youc can check the pins inside but if you see a bend one its still hard to fix.
I would try to rma if you have warranty 🙂
Just to be sure, you dont have a "sagging/hanging" card? Maybe you need to support it , depends on your case.
Did you use all the power cables correctly?
========
I personally would recommend you not to spam the board, write in wrong sections and give all your system info in a good structured way.
