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i have a question about crossfire and shared ram?

post #1 of 8
Thread Starter 
how come when in crossfire the ram is shared, i.e. i have 6970s in crossfire and they have 2gigs of ram each it adds up to 4 gig, but they have a shared mem pool of only 2 gigs. Why do they not stack to 4gigs and will their ever be a way to use all 4gigs
post #2 of 8
I'm not sure about this, but the only RAM that is actually used is the RAM in the master card. The master card is basically the first card in crossfire and handles the data going between the cards and deals with the crossfire stuff.
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post #3 of 8
Textures and all the data need to be duplicated on each card to render the screens, this means the memory doesn't stack.
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post #4 of 8
Thread Starter 
but why cant it use all 4 gigs (not that its needed in the games i play) but i was wondering why it cant
post #5 of 8
That's the thing, it *IS* using that much. It's using the same amount on each card for textures and so on, add in the extra memory and resources used by the primary card to control the second and it's using plenty of memory.

When the x-fire link has about 20x the bandwidth, then it'll have the speed to more effectively pool the memory.
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post #6 of 8
Thread Starter 
Quote:
Originally Posted by allikat View Post
Textures and all the data need to be duplicated on each card to render the screens, this means the memory doesn't stack.
so your saying the data that is rendered on the second card uses the ram to sink it withthe first card? im confusing myself
post #7 of 8
Thread Starter 
ok i get it now thank you + 1 rep to ya
post #8 of 8
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