Overclocking Noob needs help lol

[dragoboi]

Current Specs

AMD Phenom II x4 955 BE
Nvidia GTX 550ti 1gb GDDR5
8GB DDR3 1333mhz
Stock Cooler
4 Case Fans
PSU 430w

Motherboard - Biostar TA870u3+

Question - How can i undervolt with this board. i want to undervolt to 1.3375 like it says in this http://www.tomshardware.com/reviews/phenom-ii-overclock-graphics-card,3032-7.html i know this is a different mobo but i bought based off that build and the mobo it had came DOA so i bought a different board. anyways i checked bios and found a overvolt feature but not a voltage changing future and the software it comes with doesnt let me decrease voltage only increase.

 

[captjack5169]

why undervolt?

 

[dragoboi]

My temperatures are a bit out the roof. 40 celsius idle and as that link shows they hit 3.8ghz at 1.3375 volt my default is 1.404