Bigshot: I used to have a Luxman amp with those. I think it may still be possible with their current series, but you have to enable it via a switch.
TickleMeElmo: Some audiophile types buy special USB cards for computers they are using for dedicated playback. Other than that, I've always been of the mind that it simpler to build a PC using Intel boards as the likelihood of issues with chips and drivers are minimised, but I'm not that experienced in building PCs. I do recall some of the early USB and USB 2.0 controllers being absolutely awful.
I was being facetious. That said the native USB plug nearest to your PCH controller (thus minimizing the length of the trace) will theoretically offer the best performance and the least steps through different logic. Some motherboards do have issues when you plug too many USB devices in.
If you are using a USB card for a computer (not sure they are even made anymore since most desktops have ten or more USB devices), it's probably going to be PCI-E these days, which means it will probably be going through the PCH lanes, onto another piece of silicon for the USB controller.