Should I connect two 4-pin EATX12V power plugs?

Question

I have an Asus P8Z68-V Pro motherboard and a Cooler Master Silent Pro 700W PSU. The PSU has two 4-pin connectors and the motherboard has one 8-pin EATX12V connector. It boots fine with only one 4-pin connector plugged into the 8-pin EATX12V connector. I wonder whether I should also plug the other 4-pin connector from the PSU into the 8-pin connector on the motherboard, that is, plug the 4-pin connectors side by side into the 8-pin connector? I have not tried because I am afraid to damage something. Also, if I should connect it, how would I benefit?

The manual (you have to select OS, select any, and then choose the English manual to reach it) says the following:

Answer 1

Speaking as an owner of the 1kW version, I can say that the two connectors you're talking about do sit side-by-side in the EATX12V port. They're split up (on most PSUs, not just the CM-SP) to allow people to use them on old motherboards where they only have 4-pin auxilliary power ports.

The pins on the connectors are "keyed" in such a way that the connectors will only go in the right holes. On some PSUs both connectors have some sort of marking to indicate which way they fit together. I can't remember if the Silent Pro's does or not but it's fairly obvious from the way they're bound and if they fit in ;)

I'd heartily suggest you plug it in. It'll give you better stability if you ever play around with the voltages... And does no harm if you don't.