У FireWire в стандарте IEEE 1394/1394a скорость передачи данных - до  400 Мбит/с
А у USB 2.0 в режиме Full-speed, 0,5-12 Мбит/с

The full-speed rate of 12 Mbit/s (~1.43 MB/s) is the basic USB data rate defined by USB 1.1.

A high-speed (USB 2.0) rate of 480 Mbit/s (~57 MB/s) was introduced in 2001. All hi-speed devices are capable of falling back to full-bandwidth operation if necessary; they are backward compatible.

Причем контроллер только для IEEE 1394