What is Light Peak?

Light Peak is a computer cable technology designed by Intel® to replace the large number of different connections found on computers and personal electronics. The initial revision supports data rates of up to 10 gigabits per second, and future versions could handle up to 100 gigabits per second. Existing connection technologies can be supported and transmitted over a cable using either electrical or optical technology. Light Peak was rebranded as Thunderbolt™ in 2011.

With input from Apple®, Intel® created Light Peak with the goal of replacing the large number of single- and multi-use connections found on computers and consumer electronics. The company hoped to replace general-purpose connections like Universal Serial Bus (USB) and more specific technologies like the High-Definition Multimedia Interface (HDMI) with a single physical interface, thereby eliminating the need for different cables. This could allow a laptop to have a single cable interface with the ability to connect to accessories like external hard drives and scanners as well as monitors, projectors, or televisions.

To support multiple devices at once, Light Peak was designed with a much higher bandwidth than competing technologies. Initial versions of the technology support up to 10 gigabits of data per second, and Intel® has claimed this could ultimately be expanded to as much as 100 gigabits per second. In comparison, USB 3.0 has a maximum theoretical data rate of 4.8 gigabits per second. Light Peak also supports full-duplex connections, i.e., data can be sent and received simultaneously. Devices can also be daisy chained, thus allowing one port to connect to multiple devices without the use of a hub.

Existing connection standards like PCI Express and DisplayPort can be sent over a Light Peak connection, so a single cable might connect a computer to both a hard disk and high definition television (HDTV). A controller chip would encapsulate these protocols and send them over a Light Peak cable to a destination device where the protocols are returned to their native state. Under this setup, existing software can be used without new device drivers. The physical connector is identical to the one used by Mini DisplayPort, and existing displays can be used in a compatibility mode.

In February 2011, the first computers and devices compatible with this technology, rebranded as Thunderbolt™, were announced. Although early demonstrations of Light Peak had fiber optic cables powered by small lasers, the first products equipped with Thunderbolt™ use more traditional electrical signals over copper wiring. Both types of connections are supported under the new standard, with each offering distinct benefits. Electrical-only connections are cheaper and can provide up to 10 watts of power to external devices, but are limited to 9.8 feet (3 meters). More expensive optical cables can support much longer distances, but cannot power devices.