In that case, it's your choice.
Overclock is better manually, so, go to the BIOS and disable power saving options. The 1st thing is know how far you can go with stock voltage, rise the multiplier in steps of 2. The default multiplier is 32 (if I am right), rise it to 34 and run stability test (primer95, y-cruncher, LinX) to check stability and temps.
Let me know the results.