I have an 8800GT 512, and I am buying a new mobo+cpu, and I was thinking that I might want to get another 8800gt, but the mobo I want to buy is the P5Q-E which says it supports Crossfire, but doesn't say anything about SLI. I am guessing Crossfire is just the name for the same thing but for ATI cards? Does it work with Nvidia cards?

Crossfire is for ATI cards only, SLI is for nvidia cards only

I am not trying to be rude, but you probably could've done a google search or read the STICKY FAQ to figure this out. Anyways good luck on your build I guess.

Intel chipsets support CF. Nvidia chipsets support SLI. Pretty simple to remember this way.

not for long i can see nvidia opining up there drivers to intel chip-sets (no licence, free, not costing intel any cash) if things dont go right for them, just like now, ill say 6 moon if ati are still walking all over them

The P5Q-E only supports Xfire at 8X-8X bandwidth. It's not a good board to Xfire with.

That's 8x PCI-E 2.0 which is equivalent to 16x PCI-E 1.1 and neither of the high end ATI cards use that much bandwidth so it's fine to crossfire on.

Amazing the amount of increased interest in CrossfireX in the past 10 days. Before the 4 series, everyone was SLIing. Wow, amazing what a top notch 'affordable' video card can accompolish. AMD/ATI made a great move with this. What's next.

I've read this comment posted over and over again thru these forums and I'm not quite sure that I agree.

Just because a video card is labeled as being 16x PCIe 2.0 does not mean it actually uses all the bandwidth available in 16x PCIe 2.0 lanes. The label just means that the video card is compliant with that spec.

The P5Q-E uses the P45 chipset which is PCIe 2.0 and PCIe 2.0 effectively doubles the bandwidth of PCIe 1.1. Last I read, gpu's and video cards did not even use (or barely used) all the bandwidth available with the 8x PCIe 1.1, let alone the bandwidth available with 8x PCIe 2.0. So, with that said then 8x-8x PCIe 2.0 is the same as 16x-16x PCIe 1.1; which would MORE THAN ENOUGH for a Crossfire situation on any P45 mobo.

^^

Check out this review, especially the Crysis page.

http://www.tweaktown.com/articles/ [...] index.html

Interesting article, good comparison of the Crossfire performance difference between the X48 and P45 chipsets. Thanks for the link.

I don't think intent and purpose of the article was to show the performance differences of running Crossfire in 8x-8x compared to 16x-16x as much as it is highlighting the performance differences between the enthusiast level X48 chipset to the mainstream P45 chipset.

I'd be interested in seeing the same gamut of tests with the 4870 in Crossfire rather than the 4850's. The 4870 in Crossfire on a P45 mobo would get much better results.

One thing's for sure, if you want 4850's in Crossfire, then the X48 chipset performs better than the P45.

That's wrong. P45 itself perform just fine. Old 3850/70 do not bottleneck at all, since they're not powerful enough to saturate the pcie bus. 4870 will be bottlenecked even worse than 4850.