Ok, say i got a sli mother board, but i only use it for one video card. First, will this work with only one video card? Secondly, do you think that i would have to replace the motherboard for a better SLI in the future?
Ok first of all what motherboard is it.
Secondly why do you buy a SLI board if you are going to use only one card. I suggest you get another card later for better performance.
Now the answers to your questions.
Yes you can use only one card on a SLI motherboard regardless of ATI or nVidia. All it needs to be is PCI-E.
And yes sometime in the future you will need to replace your motherboard it is unavoidable because of advancements in technology.