Im trying to get to grips with all the new kit available on the market and have a question concerning SLi and crossfire.
If I get a SLi board its ok to use just one card right?
If I get a SLi board can I use an ATI card on it?
Also will the back slots on any standard ATX case fit the positions of pcIE slots and double size graphics cards? Just want to be sure;)
Yes to all your questions. 
Ooo thats great. But im guessing i couldnt use 2 ati cards with the SLi board as they would need the crossfire system right?:rolleyes:
[QUOTE=Tommy the commie]
Ooo thats great. But im guessing i couldnt use 2 ati cards with the SLi board as they would need the crossfire system right?:rolleyes:
[/QUOTE]
Affirmative
The way it stands right now, you’ll need a Crossfire motherboard OR and Intel i975X motherboard to do Crossfire. We may eventually see the i975X support SLI, but for right now, it’s a no-go. You’ll have to have an nForce 4 SLI…well, at least officially. Asus, MSI, and DFI all have nForce 4 Ultra motherboards that seem to encourage SLI or pseudo-SLI (you can mod the DFI NF4 Ultra to be an SLI board).
You can use an ATi card in an SLI motherboard, and an nVidia card in a Crossfire motherboard.
Crossfire motherboards typically have the primary PCIe x16 slot as the second one, but check your manual. You will need a Master Radeon X1000 series card if you run Crossfire. Additionally, Crossfire is still getting the kinks worked out of it, so even if you want it, you may not want to jump to a full-fledged CF setup immediately. Right now, the only board that the reviews agree on for running Crossfire is the Asus A8R-MVP.