Question about psu

[marijuanaking]

Yo. I'm building a new high end computer and I have a question about the psu. I am going to be running two psu's. One on the top and one on the bottom. The bottom one is where i'm going to hook up my motherboards power, along with two of my graphics cards. On the top one I am going to hook up my other two graphics cards along with my water cooling system and all the other small power plugs for the computer. When I hit the power button will they both power up at the same time. Or will just the bottom one because its hooked up to my motherboard. If you could help me get a better understanding of this that would be great.

My build consists of:

MB: Rampage 4 Extreme
CPU: Core i7-3970X Extreme Edition
Case: Rosewill BLACKHAWK-ULTRA Gaming Super Tower
GPU: Nvidia Geforce GTX 690 Hydro Copper Signature x4
PSU: Rosewill LIGHTNING-1300w
SSD: SAMSUNG MZ-7PC512B x2
RAM: CORSAIR Vengeance 64GB

Also I would like to know. Do I have to plug in power to the 4 pin cpu power plug thats next to the 8 pin? And do I have to plug in power to the 6 pin power next to the pci express??

 

[prototype18]

Well u need this http://www.frozencpu.com/products/5637/cpa-167/Lian_Li_Dual_Power_Supply_Adapter_Cable.html

So they can both power up

 

[clutchc]

+1^
The 2nd PSU needs to get the signal from the board to start. Hook up the top PSU to the pigtailed 24 pin connector.