I've been using my Z-5500's in my mac for quite some time now and have loved them for music and movies. Unfortunately I can't fully utilize them in games, because optical can't do surround sound encoding on the fly (or something like that). So I am forced to use the Z-5500's analog miniport jacks if I want surround sound in games. This means I need a card that supports these jacks. I've searched all over and lots of people have been having this problem. I mainly game in Windows, but with more and more games coming out for Mac it would be ideal if the card worked in both OSs. I haven't found anything that meets all my requirements yet, but this is what I have found. The PCIe X-fi surround sound card by Creative. http://us.creative.com/products/product.asp?category=209&subcategory=669&product=16770 Has anyone put this in their macpro? How does it work in XP with games and does it affect the OS X side?