The size of the memory on the card has nothing to do with the speed of the care, nor its type. That's just plain nonsense. The memory is used to store information needed by the card to render and perform the graphics. Memory memory means that the card can handle higher resolution textures, for example. Or more textures at the same time, and so on. It does not matter what the speed of the card is nor the quality, nor if it is a Geforce FX card or a Geforce 6600.