TweakTown posted an article on the Interweb yesterday, demonstrating the performance between P45 and X48 in Crossfire.

For those of you who don't know - P45 is the mainstream board, and X48 is the enthusiast or extreme board. P45 is a 65nm chip, and X48 is a 90nm chip - so P45 seems to have the advantage here.

P45 has a PCI-E x16 slot, but when Crossfire'd it turns in to 2x PCI-E x8 slots - so it doesn't have the bandwidth - X48 has 2x PCI-E x16 so in theory this works better. TweakTown want to find the difference between 8x/8x and 16x/16x...

It turns out that X48 makes a big difference with Crossfire and if you're going down the Crossfire route then it's worth spending the extra few squids on an X instead of a P.

http://www.tweaktown.com/articles/1472/ ... index.html

That's quite a big difference, I didn't expect it to be so great. It would be interesting to see single card performance aswell. Unfortunately, I don't think mATX X48 boards exist.

What about that sweet little LanParty board you were looking at? I'm sure that was X48 right?

Nah, that was a new P45 board.