512 and 256

hey i have a kingston 512 hyper x ddr 400 and a 256 crucial ddr 233...would it be better if i run the 512 alone or run with the 256 too.....they btoh can run at 3-3-3-6

Can it run at the same speed? if yes, why not. More memory means more overall system performance. But, if the 256 makes you have to run much lower FSB, I don't think it's worth it.

Do you have many programs opened while working?
If yes, keep both sticks in.
If no and wants to o/c higher, take the 256MB out.

I have both in. (recently got a stick on Kingston 512MB for $60 total after rebates. ^_^. shop.kingston.com --> in the "special" section)

not o/c-ed very high but with all aggressive settings.