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Originally Posted by Questor  (snip) For the record, USB 2.0 delivers 48MB/sec while Firewire only delivers 40MB/sec. In other words, USB 2.0 is better suited to recording than FireWire due to the reduced latency (if any at all). MusicElectronix needs to learn to check his background information before opening his mouth with such definitive statements. |
Data transfer bandwidth has almost nothing to do with latency until you're getting close to the limit of the format. For the record, USB 2.0 is theoretically 480 MBits/sec, which is 60 MBytes/sec, and Firewire is 400 MBits/sec, which is 50 MBytes/sec. Also for the record, a 192kHz/24-bit mono track is about 0.6 MBytes/sec worth of data (and that's the highest quality most interfaces can record at). Ignoring oversampling, control codes, antialiasing, and all that jazz, Firewire can transfer over 650 tracks of mastering-quality audio simultaneously, while USB can manage 800 tracks at the same quality. Theoretically, of course. Lack of bandwidth should never, ever be an issue when you're talking about latency.
Of course, that's all theoretical statistics. In reality, both formats are usually limited to 18-24 tracks per port. In this realm, Firewire is usally regarded as king. USB relies on the computer's CPU to handle data negotiation, which is already overtaxed with processing Windows, your sequencer, your background software, your plug-ins and whatever the hell else is running. Firewire has the two devices (in this case, your Firewire card and your interface) work out which will process data negotiation more efficiently between the two of them. In real-time, multi-track recording situations, this makes for a much more stable interface and leads to less latency and less artifacts.
I'm not saying the Firewire is most definately better and that should be the first thing to look at when choosing an interface. In fact, in low-level applications like a home project studio doing less than 12 tracks at a time, Firewire vs. USB 2.0 is a pointless argument, because you won't be overtaxing either format. As long as you don't go for USB 1.1, it doesn't matter what kind of cable is between your interface and your computer at this level. The big thing you need in home studio interfaces is good driver support, good A/D and D/A conversion, and enough inputs.
