USB 2 is a poorly executed hack perpetrated by Intel purely because they couldn't handle having to pay the FireWire licensing fees.
FireWire (even the 400 Mbps 1394a version that is currently shipping) is superior to USB 2. It has several important advantages, perhaps the most important being that it is root-independent.
FireWire explicitly includes peer-to-peer transfer. You do not need a computer to hook FireWire devices together and let them communicate. On the other hand, USB is explicitly designed as a computer peripheral bus--the root node must always be a computer. Without a computer powered on and managing the Universal Serial Bus, it's useless.
FireWire's isochronous support came first and is more robust than USB's. Up to 90% of each USB frame is reserved for isochronous data (combined with interrupt packets like mouse clicks), compared to 80% for FireWire. However, USB's isochronous cycles trigger every millisecond, where FireWire's trigger eight times per millisecond, making more efficient use of bus time by dividing it into smaller intervals. FireWire's higher bus speeds make it a far more robust isochronous transport.
FireWire allows bridging buses together, up to 1023 of them. There are already USB bridges in discussion (perhaps available), but they skirt the edges of the specification. If you can plug a single device into two computers through USB, each computer will see the peripherals downstream from the "bridge," but the bridge has to include lots of special logic so the two computers don't try to use the same peripherals at the same time. I'd be awfully wary of plugging a disk drive into such a setup.
It's hard to say whether USB 2.0 will overcome these deficiencies--but if it does, it will basically be FireWire. Intel was a great proponent of FireWire until just about the time the company realized they were going to have to pay royalties on chips like every-one else. That's when Intel decided that FireWire was useful only for consumer electronics (like camcorders), but the quickly-invented USB 2.0 would be the preferred way to connect printers, scanners, disk drives, and so on. Since the licensing fee matter was decided, all those companies that had been ambivalent on FireWire are again behind it--including Microsoft--except Intel.
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USB 2 is a poorly executed hack perpetrated by Intel purely because they couldn't handle having to pay the FireWire licensing fees.
FireWire (even the 400 Mbps 1394a version that is currently shipping) is superior to USB 2. It has several important advantages, perhaps the most important being that it is root-independent.
FireWire explicitly includes peer-to-peer transfer. You do not need a computer to hook FireWire devices together and let them communicate. On the other hand, USB is explicitly designed as a computer peripheral bus--the root node must always be a computer. Without a computer powered on and managing the Universal Serial Bus, it's useless.
FireWire's isochronous support came first and is more robust than USB's. Up to 90% of each USB frame is reserved for isochronous data (combined with interrupt packets like mouse clicks), compared to 80% for FireWire. However, USB's isochronous cycles trigger every millisecond, where FireWire's trigger eight times per millisecond, making more efficient use of bus time by dividing it into smaller intervals. FireWire's higher bus speeds make it a far more robust isochronous transport.
FireWire allows bridging buses together, up to 1023 of them. There are already USB bridges in discussion (perhaps available), but they skirt the edges of the specification. If you can plug a single device into two computers through USB, each computer will see the peripherals downstream from the "bridge," but the bridge has to include lots of special logic so the two computers don't try to use the same peripherals at the same time. I'd be awfully wary of plugging a disk drive into such a setup.
It's hard to say whether USB 2.0 will overcome these deficiencies--but if it does, it will basically be FireWire. Intel was a great proponent of FireWire until just about the time the company realized they were going to have to pay royalties on chips like every-one else. That's when Intel decided that FireWire was useful only for consumer electronics (like camcorders), but the quickly-invented USB 2.0 would be the preferred way to connect printers, scanners, disk drives, and so on. Since the licensing fee matter was decided, all those companies that had been ambivalent on FireWire are again behind it--including Microsoft--except Intel.