Note that stock voltage is not the same as auto. If you don't change anything in the bios it'll put whatever it feels like through your cpu. CPU-Z will tell you what the current vcore is, check that this is well under 1.5V.
Otherwise, as above, if it's stable it's fine. If it's not stable, more voltage may help, or less voltage may help, or any mad combination of options in the bios.