OC section of the MSI DKA790GX Platinum is called the CELL Menu. This is where the magic takes place.
- see CPU-Z default multi and fsb also voltage and then boot, go bios menu cell :
- amd cool n quite disabled
- let adjust cpu fsb frequency at 
- adjust cpu ratio from auto to [many option]
- try oc without adding voltage
Or read this article review your mobo : http://overclockersclub.com/reviews/dka790gx/