I'm thinking about buying a Sapphire HD 7970 3GB GDDR5 for my system. I have the Gigabyte GA-990FXA-D3 board though. I saw that the Sapphire needs 1 PCI-express 3 slot. And I can't discover whether this board supports this card.
Could you tell me whether this card can function well on this board and will a future crossfire setup be possible, or will I run out of slots?
That card will work fine in that board. No video cards come close to saturating a pci-express x16 v.2.0 so v3.0 is not even relevant for the current generation of cards. Probably for the next gen even. The fact that the card supports it does not mean it requires it.