Do gtx 295 only use half the vram?

[Affe99]

I was just wondering if the gtx 295 use's only half of its 1792MB vRAM? I have done some research on dual gpu cards and most of the people say that dual gpu cards only use half of the vram. But a "friend" of mine says that the gtx 295 is diffrent and uses all of its vRAM is this true?

 

[mactronix]

When you are using 2 GPU's each card has to have a copy of the information the other GPU has in order to know what the other is doing.
Be that 2 actual cards or 2 chips on on card.
So that means that if you have 2X 1GB of memory, that would be 1GB for each chip total of 2 GB for the card/cards.
Now say a game sends 512mb of info to the card, each 1GB memory allocation will receive a copy so now you have 1GB left of free memory and not 1.5 GB.

Not sure if that makes sense to you or not ?

Mactronix