Shoutbox

i recently got a Inno3D Tornado GeForce FX 5200 graphics card.
on the box, its written 128 MB DDR. but in my computer, it says the card is 256 MB. even the shopkeeper told me its 256 MB. i wanna know what exactly is the card of.
i searched the net and everywhere it says 128 MB.
also, on the box, it says its AGP 8X but i have it installed in a PCI slot.
but then why does it say 256 in my comp.
can someone clear this up?