In 2009, Intel demonstrated the first ever optical interconnect for computer peripherals: Light Peak. It promised speeds of 10Gbps symmetrically — 20Gbps in total — over a single 30-meter-long fiber optic cable. Light Peak was low-power, and it used clever multiplexing to run multiple protocols over a single 62.5-micron fiber. Better yet, Light Peak could even piggyback on top of USB cables, providing socket backwards compatibility — and to top it off, Intel said that 10Gbps was just the beginning: 100Gbps would be possible in the next decade! Light Peak, in short, delivered a delicious hint of what a fast, flexible, and future-proof interconnect could do. Then Apple came along and ruined everything.

To be fair, there was never really any chance of Light Peak, in its original form, being built into Apple’s latest products. Optical switching and interconnects are only found in enterprise-level routers for a reason: playing with light is expensive. Light Peak was summarily binned and Thunderbolt was born. Thunderbolt is a copper wire version of Light Peak — it uses much of the same technology, but it does away with the optical/electrical interface. Apple wanted to include a next-generation technology to rival or even beat USB 3.0, and a cut-down version of Light Peak was the only real option. In the same way that Apple championed FireWire for the replacement of parallel SCSI, Thunderbolt is meant as the next big thing in video and audio peripheral interfaces.

Just like FireWire, though, Thunderbolt is off to a slow start. Even in its non-optical, crippled copper state, Thunderbolt is prohibitively expensive. USB 3.0 controllers cost just a few dollars, while Thunderbolt hardware, we’ve been told, cost no less than $90. Matrox’s new line of Thunderbolt-enabled products are $200-300 more than the eSATA or USB equivalent! As a result — and FireWire had the same problem — we will only see Thunderbolt-enabled devices where the price of the controller can be transparently absorbed by a high list price: video cameras, high-end audio gear, and so on.

Then there’s the matter of whether Thunderbolt is actually necessary, or just a sexy-sounding marketing slogan that can be slathered over the Apple website — it sounds pretty awesome when you say it aloud, too. When Apple extolled the virtues of FireWire, it filled a gap — USB just wasn’t fast enough for professional applications — but the landscape is entirely different today. Over 6 billion USB devices have been sold to date, and support for the standard is as close to ubiquitous as we’ll ever get. USB 3.0 is already in the market — HP, the world’s largest PC manufacturer, opted for USB over Thunderbolt — and it’s backwards compatible with every USB device ever made. Most importantly, though, USB 3.0 is more than fast enough for current and near-future applications. There are some latency issues that make Thunderbolt more attractive for professional video and audio work, but as soon as Intel and AMD build USB 3.0 support into the chipset, the difference between the technologies will be negligible.

The final piece of delicious irony, though, is that Light Peak was originally designed to accommodate both optical fiber and copper wires in the same cable. Light Peak, in its first incarnation, was socket compatible with USB, providing a perfect upgrade path from USB 2.0, to 3, and eventually to an optical Light Peak 10Gbps interconnect. You could buy an external USB 3 hard drive, and plug it into a Light Peak socket — and you could plug an external monitor into your other Light Peak socket without issues. Instead of ushering in a beautiful, cross-platform, next-generation interface that could revolutionize the pain of peripherals, Intel kowtowed to Apple and created a new socket that only a tiny fraction of Mac OS X users will actually use. Instead of sticking to its guns with the Light Peak fiber-and-wire dream combo and slowly weaning the world off USB, we get a toothless and useless Thunderbolt.

But hey, Intel won’t have given up its optical interconnect entirely — and with the recent invention of cheap and fast graphene optical modulators, who knows what’s around the corner?