I noticed that the Gigabyte board advertises for ATI rather than NVIDIA. Is there something embedded in the mobo that would make one card faster than the other, or is it just a sponsorship thing?
No. The gigabyte won't do 3-way purely and get a pretty nVidia sticker, so...how would you spin it? Can't.
ATI don't put restrictions on using their capabilities. Because there aren't much. Plug it in, they work. nVidia? It's not sponsership, it's their sick game of allowing you to use them or not.
You can put 3 nvidia cards in both. You can do SLI even. Just one is pimping their x16 by 3 sales pitch and pulled it off and get a sticker. Two x16 and one x8 at the double pumped PCIe 2.0 standards is SLI still...oh wait...two cards still is I thought.
Sales my friend. You get a picture of a sticker on a website if you buy into it.
Case in point: PCP&C 750W Power supply. One is red, one is not. Why is red cheaper? Same exact unit, different prices. And now there's a blue one that costs more than both...weird shit.