Opteron overclock in Linux via software?

So im thinking of getting ASUS KCMA-D8 to flash Libreboot in it and was wondering that if i buy 4000 series Opteron for it can it be overclocked via software?

Thinking of buying something like 4340 or 4280 Opteron.
Those are quite weak cpu’s stock so was wondering if i can squeeze any extra out of those.