Ok so here's the deal, I've been reading all over about ATI's crossfire and I've heard three different things about the kinds of cards that can be used together:

1. The cards must be identical
2. They can be different but must be of the same line (you can have a 2600XT and a 2600Pro)
3. They can be any combination of crossfire ready cards (you can have a 2400XT and a 2600XT).

I'm pretty sure number 1 is completely false but I'm unsure of 2 and 3. Does anyone know which is true?

By the way, from what I hear SLI will only work with identical cards, but I'm unsure of that as well.

SLI ONLY works with identical VGAs

Originally Posted by E_design

SLI ONLY works with identical VGAs

Right. But what about crossfire?

1. The cards must be identical
2. They can be different but must be of the same line (you can have a 2600XT and a 2600Pro)
3. They can be any combination of crossfire ready cards (you can have a 2400XT and a 2600XT).

1. true
2. False
3. False.

Crossfire and SLI dont differ in technology, only features. With both, you need identical cards of the same chipset, so no an x850xt and an x850pro will not function together. And you need to make sure they are both certified for crossfire, and that you have the power to give to the extra video card.

They don't make it easy to understand. Back when I was building PC's for a living, I think I remember needing to use a crossfire edition as a master card and a crossfire ready as a slave card. I would definitely check out http://ati.amd.com/technology/crossfire/faq.html if you haven't already.