Mark Twain wrote “Thunder is good, thunder is impressive; but it is lightning that does all the work.” That’s the quote that popped into my mind this week as Intel and Apple rolled out Intel’s new 10Gbps photonic I/O technology, code named Thunderbolt (the I/O technology formerly known as “Light Peak”). Now there’s no denying that Intel’s Thunderbolt is fast. It’s more than 20x faster than good “old” USB 2.0 and it’s 12x faster than FireWire 800. But it’s only 2x faster than the new USB 3.0 standard that’s starting to appear. So it’s still a horse race, folks.
I must admit to being somewhat confused by the few hazy details leaked about Thunderbolt before the introduction. Intel does a lot of research into photonic I/O at the chip, board, and system level so those technologies seem to have become all muddled in my own head.
It’s clear that photons are better when it comes to high-speed serial communications over any sort of distance.
For example, photonic I/O is the clear winner and the only force in the universe for long-distance communications. Optical fibers have replaced long submarine phone lines and microwave communications towers alike. I can still remember photos of the railroad plow/ditch digger Quest used to install fiber along railway rights of way. I can also remember the microwave relay towers along I-25 running from Fort Collins to Denver, Colorado. Those towers are gone now, replaced by cellular base station antenna farms all linked by underground fiber. So photons win in the distance marathon. But there’s a price for photonic I/O and so far, electrons have always won at the chip, package, board, and system level with a few exceptions such as in the storage arena where Fibre Channel won, but now clings to life.
As for PC-class systems? We’ll see. Intel’s Thunderbolt technology is first appearing on Apple’s high-end MacBook Pro line of laptops, selling for $1200 to $2500. Thunderbolt-connected peripherals are certain to follow. Whether they will win the day or not remains to be seen. Meanwhile, the introduction of Thunderbolt last week certainly cleared up one of my misconceptions. The PC interface to Thunderbolt cables is actually electrical and uses an electrically modified DisplayPort connector.
The Thunderbolt controller, which lives inside of the PC, accepts I/O traffic from either a PCIe port or a DisplayPort interface. The electron-to-photon-and-back-again conversion actually happens inside of the cable, which makes a huge amount of sense because splicing high-performance photonic-conversion devices to optical fiber is an art. So the port controller and connector inside of the computer can be relatively inexpensive and the cable—let’s just say that the cable is a likely candidate for setting a new high in the price of Monster Cable products.