FireWire 400 can transfer data between devices at 100, 200, or 400 Mbit/s data rates (actually 98.304, 196.608, or 393.216 Mbit/s, but commonly referred to as S100, S200, and S400). Although USB2 claims to be capable of higher speeds (480mb/s), FireWire is, in practice, faster. Cable length is limited to 4.5 metres but up to 16 cables can be daisy chained yielding a total length of 72 meters under the specification. FireWire 800 (Apple's name for the 9-pin "S800 bilingual" version of the IEEE1394b standard) was introduced commercially by Apple in 2003, allows an increase to 786.432 Mbit/s with backwards compatibility to the slower rates and 6-pin connectors of FireWire 400.
A 9-Pin FireWire 800 connector The full IEEE 1394b specification supports optical connections up to 100 metres in length and data rates all the way to 3.2 Gbit/s. Standard category-5 unshielded twisted pair supports 100 metres at S100, and the new p1394c technology goes all the way to S800. The original 1394 and 1394a standards used data/strobe (D/S) encoding (called legacy mode) on the signal wires, while 1394b adds a data encoding scheme called 8B10B (also referred to as beta mode). With this new technology, FireWire, which was arguably already slightly faster, is now substantially faster than Hi-Speed USB.