It depends if its 512x2 or 1024 as one piece
If it's 1024 as 1 piece, it's worth
But if it's 512x2, I'd rather you stick to 512, unless the mobo has dual-ddr support where 512x2 = 1024x1
512x2 is slower than 1024 a stick, because computer randomly puts stuff on your RAM, and re-reading stuff on the ram on seperate sticks would cause it to *slow* down a *bit*
Correct me if I'm wrong though
p/s : I'm running 512x2 as dual-ddr