Overclock 8350 and m5a97 evo r2.0

Use AMD's overdrive software to OC the processor . Its in Catalyst control center , and should have installed with your motherboard drivers
It sets the voltage to a maximum of 1.4 volts [ by default]
and ramps up the multiplier step by step while checking temperatures .

a few mouse clicks is all it takes
 
i overclocking the CPu, using following setting
Vcore- 1.44
24x200

when i disable 3 to 8 core. same frequency gain, and temp reach max 45C

what is difference b/w 2 core (enable) and all 8 Core (enable)

CPU Temp 82C

CPU Core Package 72C
Noctua D15
is it safe,