Firewire

Firewire, officially IEEE 1394, is an interface standard similar to SCSI and primarily was a competitor of USB. It is known for having high speeds and was developed by Apple as a replacement for the bulky and unwieldy parallel SCSI in wide use in the 1980s and 1990s. It achieved widespread success in niche consumer markets but never fully displaced USB in any area.

Differences from USB

Firewire does not use hubs and host controllers, instead operating on a daisy chain system with the bus being cooperatively managed and shared between devices. It thus can operate without sapping much resources from the CPU or system memory, and allows point-to-point device communication. Up to 63 devices can be attached to a single firewire bus.

Support in IRIX

The Chimera systems and the O2 each have some level of limited official support for Firewire. The O2 only officially supports firewire cameras. Not storage. The Chimera systems (Tezro, Fuel, Origin 350) all support firewire mass storage.