How FireWire Works

By: Jeff Tyson & Julia Layton

FireWire Specifications

The original FireWire specification, FireWire 400 (1394a), was faster than USB when it came out. FireWire 400 is still in use today and features:

  • Transfer rates of up to 400 Mbps
  • Maximum distance between devices of 4.5 meters (cable length)

The release of USB 2.0 -- featuring transfer speeds up to 480 Mbps and up to 5 meters between devices -- closed the gap between these competing standards. But in 2002, FireWire 800 (1394b) started showing up in consumer devices, and USB 2.0 was left in the dust. FireWire 800 is capable of:


  • Transfer rates up to 800 Mbps
  • Maximum distance between devices of 100 meters (cable length)

The faster 1394b standard is backward-compatible with 1394a.

In the next section, we'll get deeper into the FireWire vs. USB debate.