What is Thunderbolt?

Apple's latest lineup of MacBook Pro laptops are the first products to feature Thunderbolt, which Apple describes as "the most powerful, most flexible I/O technology ever in a personal computer". But, what exactly is it and what does it mean for you?

Developed under the code name Light Peak, Thunderbolt is an example of I/O technology, which means that it offers a two-way transfer or data between your computer and other electronic devices. Using high-speed optical cable technology, Thunderbolt delivers a high bandwidth of 10Gb/s (on a cable up to 100m in length), which means that the technology has the ability to transfer a full-length Blu-ray movie in less than 30 seconds, which is pretty zippy. That's more than 20 times faster than USB 2.0 and more than 12 times faster than FireWire 800. And if you thought that was fast, then you'll be pleased to hear that the technology has the potential to scale to 100Gb/s over the next decade.



Already used extensively by the telecomms industry, optical cables use light instead of electricity to transmit data which means that they're not subject to the same restrictions as electrical cable when it comes to limits on speed and length. As a result, more data can be transferred at higher speeds over greater distances. As well as optical cables, the new technology also suports electrical cables. Thunderbolt's two-way, high-speed transfers means that you can daisy-chain a range of devices and a display, without the need for a hub.

Developed by Intel, in collaboration with Apple, Thunderbolt is based on two existing technologies - PCI Express and DisplayPort. PCI Express is the tech that links all the high-performance components in a PC or Mac, and its inclusion in Thunderbolt means that you can hook up devices such as external HDDs to your MacBook Pro at the same high speeds as well as using existing USB and FireWire peripherals, albeit using adaptors.

DisplayPort is the connector used by Apple, and many other brands including Dell and Lenovo, in place of VGA and DVI ports (Digital Visual Interface). The Thunderbolt's built-in DisplayPort technology means that you can plug a Mini DisplayPort screen straight into the Thunderbolt port, or connect DisplayPort, DVI, HDMI or VGA displays using an adaptor thus cutting down on the number of holes you need on the side of your laptop's chassis.

As well as being fast, the Thunderbolt connection can also run multiple protocols using a single cable so that you can connect to lots of different types of kit such as displays and docking stations.

When it comes to the actual harware involved, Thunderbolt comprises a controller chip and an optical module, with the latter using tiny lasers and photo detectors to convert electricity to light and vice versa. The chip is where the protocol-switching wizardry takes place enabling you to plug in peripherals like projectors without the need for a different connector.



In short, what Thunderbolt means for you is smaller, slimmer laptops with fewer connections and in turn, fewer cables. It also means that media types will be able to connect to high-bandwidth audio and video capture and mixing devices. Although Apple is the first brand to launch a product with a Thunderbolt port, the connection won't be exclusive to the Cupertino brand, with other manufacturers, such as Western Digital, expected to include the technology in upcoming products. Can Apple play a large role in the standardisation of Thunderbolt or will it go the way of FireWire? We look forward to finding out.