Skunk is correct, of course... nVidia don't licence SLI on anything but their own chipsets, don't licence Crossfire, and their drivers check for a controller chip nVidia install on their Mobos. So while it's possible to hack, it's not easy and not supported - So if/when there's an issue it's all on you to figure out.
On existing AMD and Intel chipsets, you can use Crossfire, and that's it.
Though be advised, from now on that is changing with the new (Core I7) Intel X58 Chipset: Intel played a little game of Brinksmanship on nVidia and threatened to withold licence for the new Intel socket. That got nVidia's attention *really* *really* *fast*, since nVidia would have been stuck with only supporting up to current LGA775 sockets, which are now a dead end, and AMD processors, who are nVidia's main competitor in the Graphics space. Pretty bad position to be in, especially when your CEO enjoys pissing people off.
There was a little talk of nVidia buying Via and entering the CPU space...
But once everyone recovered from the ensuing hysterical laughter at the thought of someone trying to make Via into a challenger to Intel, Jen-Hsun Huang (nVidia CEO and 'The Man Who Plans To make The CPU Obsolete')
sent his execs over to Intel... The deal they cut allows for Motherboard makers to pay nVidia for a licence and controller chip to run SLI on specific models. So on X58 boards, you can run both - depending on the model
and whether the maker chose to licence that particular board with nVidia.
I would expect the highest end enthusiast boards will be able to run both. (And Yes - the benchies I have seen indicate that Core I7/X58 scales very nicely with multiple GPUs.)
Otherwise, people will likely still have to choose ATI or nVidia.
....and next on 'As The Tech World Turns':
- Will Eric Schmidt's (Yahoo)
package be bigger than Bob Willumstad's (former AIG chief)
- Will the American Taxpayer take another round of Financial Sodomy for the Auto makers now that the Financial guys have 'Swallowed' (sic) what they can??? And who's that shadowy industry in the background hungrily eying the scene while clutching at itself!?!?!
- How Many Cars will a certain soon to be former President 'grow' in his yard??
TUNE IN AND FIND OUT!