why c533? because your m/b only support 8x multiplier? no bios update support.
that was the situation i had before. can't find c533a anywhere or the price is too much.
get c566a with a cheap soltket, put it in, it worked,it post c566 by default. i used the B21 trick on the soltket. it post 850. is this helpful for you.
c566@850 soltket vcore by jumper @1.9v. very stable!!!!