I highly advise against putting Linux and X-Fi cards anywhere near each other. Creative Labs have proven over the years to be resistant to open source software and driver support for such. As a result the quality of said *nix drivers has been a cursory token gesture at best. It took 3 years after release to get even the current basic driver up to a point where it could be merged into the kernel. And before then making the card work at all required either many hours of compiling and kludging or an earlier bugy binary blob that required the use of a specific distro and kernel revision to function. Creative Labs windows drivers have never been terrific either. And worse the company has a policy of enforced obsolescence through strategic dropping of driver support. They have essentially been re- branding the same architecture as new products. Then dropping driver support for the old line, forcing upgrades for their last three product generations. If you need evidence of their poor business practices, then feel free to google away for complaints people have had.
Myself, I use an Asus Xonar D2X. http://uk.asus.com/product.aspx?P_ID=ZBWhAEnH6nDOB00E&content=overview It has superior audio quality over the X-Fi. Has always worked out of the box with Linux, using an open standards driver interface. I've not had a single issue with it after a couple of years of ownership. Usefully, is easily configurable between its various analogue (5.1, 7.1, 2.0, etc) and Digital coax /fibreoptic output modes with a single click from the Ubuntu indicator area GUI as well. -- 9xx SOLDIERS SANS FRONTIERS
