We already reported that AMD company decided to add in the south bridge SB750 some unique abilities, which allow to completely open the overclocking potential of phenom generation processors .
For achievement of maximum result user have to use effective cooling and also to increase the core voltage.
As asserts associate motherboard on base of 790GX chipset overclock the processor phenom X4 9850 Black edition (2.5 GHz) to 3.4 GHz with air cooling.