Building a new box - ATI vs Nvidia?

So I'm about to order the parts to build a new gaming rig and I thought I'd better check to see what's the best compatibility for Kubuntu. Right now as it stands the processor will be an AMD Phenom 9600 2.3Ghz, which is a quad core. I'll have 2Gb DDR2, and dual ATI Radeon 3850s.

I know XP and my Windows-based games will scream on this machine, but I want to dual boot to Kubuntu for everything else. Will the dual ATI CrossFireX setup give Linux indigestion? Would a dual Nvidia SLI card setup be any better?

Just as important, this mobo has an onboard s/pdif optical output. Will Kubuntu support that and provide full surround sound to the s/pdif? Am I asking too much of it?

I can tell you from experience and personal observations that nVidia users generally have fewer problems under Linux. Things are definitely improving for ATI users, but ATI has not completely caught up, just yet.

Just read anecdotally that Linux does not support CrossfireX, the ATI dual card bridging technology. That might throw a wrench into things.
I wonder if there're similar issues with Nvidia's SLI?

At the moment nVidia support is far better on Linux than ATI. Because of all of the documentation supplied by ATI this should change in the future but for the moment nVidia still works out better.

On a side note I usually prefer AMD chips but at the moment they aren't up to as much as the Intel equivalent. The Phenom quads were trashed byt the Intel Q6600 and several of the Intel dual cores in benchmarks. I usually check out this site for benchmarking...

[Phoronix] Linux & Solaris Hardware Reviews

As suggested by all Nvidia graphic card give better support to Linux OS. Along with that Nvidia graphic cards are good at performance than ATI. Nvidia 7900 GTX graphic card has been said to be the best graphic card as per the review done by wellknown gaming companies.

Not only is it true what has been posted in this thread, I think you can do everyone a favor by not recommending ATI cards for Windows systems also as long as ATI is subpar.

ATI may not care about the volume of Linux users, but they certainly might care about that volume plus the volume of their combined recommendations for non-Linux systems.

ltg