I've seen a lot of forum threads on this topic but none of them has quite answered my question. I'm trying to find an external (USB or FireWire) sound card that has 6-channel-direct analog outputs for 5.1 surround sound that is BOTH Mac and Windows compatible. I need to be able to control the three channels independently in real time in Digital Performer under OS X and I need surround sound in Windows for gaming. So my question is: is there one card that can do all this? I would prefer a consumer level card instead of a pro interface, because I certainly don't need any more than 6 channels. FireWave is no good because it's not Windows-compatible (and discontinued), X-Fi is no good because it's not Mac-compatible. Using the onboard optical is no good because it doesn't support more than two channels of unencoded audio and it doesn't support Dolby Digital Live or DTS Connect to encode 5.1 in real time. I've determined that a suitable internal PCI-Express sound card does not exist, but I'd love to be proven wrong.