Technology: Apple Thunderbolt

A Port To End All Ports?

Recently, Apple launched a refresh of their MacBook Pro line of notebooks which feature a new interface port designed to connect the "next generation of high-performance peripherals to the next generation of computers".

Originally codenamed Light Peak, Thunderbolt was initially designed by Intel, and brought to market with technical collaboration from Apple. Using the same connector as Apple's Mini DisplayPort, the Thunderbolt interface combines PCI Express and DisplayPort technologies into a new serial data interface that can run over longer distances with less issue than previous interfaces, such as USB and FireWire. Since PCI Express is widely supported by most device makers, and built into the majority of modern Intel chipsets, Thunderbolt can be added to existing products with relative ease. The Thunderbolt chips fold the data from these two sources (PCIe and DisplayPort) and splits them apart for consumption within compatible devices (nom nom!)

 

The interface was originally designed to use fiber optic cable (hence the name, Light Peak), but a conventional copper wire version was developed to furnished the desired 10 Gb/s bandwidth at a lower cost. Intel's implementation of the port adapter folds both Thunderbolt and DisplayPort data together, which allows both to be carried over the same cable at the same time. A single port supports both hubs and daisy chain configurations of up to seven Thunderbolt devices, with up to two of these devices being high-resolution displays using the DisplayPort portion of the interface. Adding to the flexibility, Apple and other manufacturers sell DisplayPort adapters for DVI, dual-link DVI,. VGA and HDMI.

Originally conceived as an optical technology, then a combination of both fiber and copper, the final design of Thunderbolt was switched to copper-only connections to reduce costs by providing both data and power via the same cable, thus helping reduce the cost to the end user.

Intel and other industry partners are still trying to develop optical Thunderbolt hardware and cables. These cables will not be able to supply power, but are planned to be able to transport the signal up to 100 meters with conversion between optical and electrical signals to be embedded into the cable itself allowing the current DisplayPort socket to be future compatible.

Apple is touting Thunderbolt as the "fastest, most versatile I/O ever in a notebook", allowing for plug-and-play performance with a new generation of peripherals. According to Apple, Thunderbolt is more than 12 times faster than FireWire 800, and up to 20 times faster than USB 2.0, changing the way you can manage your digital media assets, including the ability to access multiple streams of uncompressed HD video.

Current disk speeds, however, could prevent Thunderbolt from reaching it's full potential of 10 Gb/s. Intel demonstrated throughputs at 62.5% of that peak using prototype products. A fast hard drive system such Promise Pegasus RAID or LaCie's Little Big Disk would bring this even closer to the theoretical peak.

As with any new technology, time will tell how well it will work in the practical world.