Do you even know what the hell your talking about? A P4 Board Woulden't be using DDR2 Ram zzzzzalso, when buying new ram buy the fastest, nowadays you have 667 and 800 mhz sticks and if your motherboard supports both of them, go for the 800mhz ones.
and don't bother to buy DDR3 ram, it's way to expensive. just go for DDR2[/b]
I would get these sticks of ram for your computer, it's 130$ But it's the best CAS Out of them all for the price especially :