Stock voltage on fx-6300 is 1,35v @ 3,5ghz and the best way to overclock your vishera is to disable turbo core which raises stock voltage to + 0,1v --> 1,45v for 4,1 ghz... Most of common people who have this cpu set llc at normal (about + 0,05v) and raise vcore to 1,40v @ 21x200 either 1,45v in real conditions... Of course each cpu has not the same capacities for overclocking either through voltage settings or frequency ranges... For my case i have an 8 core fx-8320 @ 3,5ghz @ 1,35v stock and i've decided to practice undervolting: the settings are: llc on normal, vcore on 1,25v and frequency at 19,5x200 and all is stable... I think that very high frequencies are meant to be for benchmarks as even at stock speeds 6 cores and 8 cores fx cpus are efficient...