Intel originally designed its Light Peak interconnect as an optical technology that would replace all other PC connections, handling everything from LAN to storage devices to monitors. But after the company unveiled it in 2009, PC manufacturers called for a cheaper electrical incarnation – i.e. non-optical – and due to other market pressures, this electrical version, renamed Thunderbolt, will coexist alongside the likes of USB.
"We started having broader conversations with OEMs and got feedback about the technology," Jason Ziller, Intel director of Thunderbolt planning and marketing told The Register this morning after a press event in San Francisco. "We started studying ways to reduce the cost, and that's how the electrical solution came about."
Aviel Yogec, the engineer who oversees the Thunderbolt project, told us that even before the OEMs weighed in, he was exploring an electrical version on copper. But the added pressure from manufacturers crystallized those efforts. "We had done [electrical] to some extent," he said. "But then we got the pressure [from OEMs]. Optical seems sexier than electrical, but eventually, when you have to pay for it and actually bring it to market, you have remove some of the cost."
Originally, Yogec and his team moved data from silicon to an on-board optical transceiver, which could then move data at 10Gbps over distances of up to 100 meters. They weren't completely sure, Yogec said, that they could achieve similar speeds over cooper. But nearly two years on, they have. Thunderbolt is a 10Gbps, bi-directional, dual-channel copper link that supports two separate protocols: DisplayPort and PCIe.
The rub is that the current Thunderbolt technology - which debuted today on Apple MacBook Pros – only works across a 3 metre cable. But according to Yogec and Ziller, Intel will eventually offer an optical cable that will plug into the existing on-system hardware, transferring data across much larger distances. "There's a variety of applications we've thought about [that require longer cables]," Ziller said. "For example, media creation, where you have long distances between video cameras and the machines they're connected to."
And eventually, the company says, it hopes to introduce an all-optical setup, where that optical transceiver sits on the PC. "We haven't abandoned the idea of a light connection," Ziller said. "We still believe that optics is in our future and will be necessary over time and will be brought in over time. We are still doing research and we will assess when its appropriate time is to bring that into the platform."
"We are still working to reduce the component cost of optical," Yogec said. "We reduced the cost significantly, but OEMs still had issues. But eventually, we will have to move to optical."
According to Yogec, the electrical version of the technology provides exactly the same speed as the optical version. The only difference is the length of the cable – and cost.
The rumor is that the idea for Light Peak originated with Apple and Steve Jobs. Ziller declined to address such rumors. But when we asked Yogec how the project began, he indicated that the idea originated somewhere outside of Intel Labs. "The idea came from somebody who said let's take all those PC cables and roll them into one cable," he explained.
Such interconnect nirvana is still a ways away. Intel says that it will continue to back USB and that it will build USB 3.0 into future chipsets. "[Thunderbolt] is complementary to USB 3.0," Ziller said. Repeatedly. ®