MSI z97 gaming 5 confusion

[ThePCNovice]

I am getting an msi z97 gaming motherboard: http://www.amazon.co.uk/dp/B00K8KPXUO/?tag=pcp0f-21 and I am a bit confused when it comes to the audio boost as you have to flip a little switch on the board and plug your molex to 3 pin adapter in for power. What does this do, it is really confusing. Thanks

 

[rujoesmith]

The switch is to change between onboard power and external power from the power supply. There is a 3pin plug on the motherboard that you can attach to your powersupply for additional power. If you have not plugged this in, leave the switch in the default position.

Refer to pages 1-25 and 1-28 for more info. http://us.msi.com/product/motherboard/support/Z97-GAMING-5.html#down-manual