Duel DDR or not?

Hey, sorry is this question have be asked tons of time.

Should i buy 1 512 DDR433 or 2 256 DDR433?

Will duel drr preforme much better the one?

EDIT: Oh, its one the A7N8X

Current Athlon processors don't really use the bandwidth of DCDDR400. So if you're trying to get 200FSB then there won't really be a difference except in Sandra. However, Barton cores might make use of the extra bandwidth. So if you plan on upgrading to Barton and don't want to fork out the $$$ for another dimm later then I would definately go ahead and get 2 sticks of 256. The price difference is pretty negligable so you might as well take advantage of the dual channel feature.