Seasonic power cable 18pin and 10pin

[MrLordMana]

Hi!
I'm a little confused...
The motherboard cable has one end that is 24 pins that goes to the mobo, and then on the other end it's an 18 pin plus a 10 pin connector splicing from that.

To be clear, an upper cable is two rows of nine, a low cable is two rows of five, and these merge into the 24 pin that plug into the motherboard.
http://cdn.overclock.net/b/b2/b2c194e6_vbattach225925.jpeg

Why is there 28 pins on the psu?
and
Do i need to plug both of them (10+18pin) or just one?

PSU is SeaSonic SS-660xp2
and MB is Asus V I I Hero

 

[synphul]

I'm not sure, there should have been instructions that came with the psu outlining what to plug where. My guess would be to plug both in. Why they're designed like that I don't know, but I would assume both plugs at the psu side should be plugged into their corresponding sockets labled M/B with the 24pin connected to the motherboard itself.

 

[Dark Lord of Tech]

Yellow = 24 pin
Red is = 10 pin on the 24 pin cable
Pink = PSU to 8 pin CPU power.