Single card [x2 vs Crossfire] two cards

[nitros85]

How does software handle a single dual-gpu card (a single X2 series card) compared to a Crossfire/SLI dual-card setup (two cards)??

My question is primarily...

If the game does NOT support Crossfire/SLI (two cards) will it treat the (x2) as ONE card, or will it treat it as two cards and only use "50%" (give or take) of its power??



I want to know because there are plenty of games in which having Crossfire/SLI does absolutely nothing.

If a x2 series (GX2, 4870x2, 5970, 5950) single card is treated by software as a very powerful SINGLE card, then awesome. 😍 If it's the exact same as having two cards in Crossfire/SLI (just saving one Pci-e slot) then that's stupid.

 

[paperfox]

If you have, say a 4870x2 with crossfire on, your computer should treat it exactly the same as if you had two 4870s. The only difference/advantage is the x2 card only takes up one pcie slot.

If using a 4870x2 card on a game that does not support crossfire I can foresee two outcomes:
1) The game gets horrible unplayable frame rates when crossfire is on.
2) The game gets as good/near frame rates as a single 4870 with crossfire on.