First Thunderbolt Peripherals Arrive, Standard's Future Uncertain
As it turns out, Thunderbolt uses what's called an active cable. Inside the cable there's a pair of Gunnum GN2033 transceivers. The company's website notes: "The GN2033 is a tiny, low power transceiver chip designed to be placed inside the connectors at either end of a Thunderbolt™ cable, enabling dual bidirectional 10Gb/s concurrent links over narrow-gauge copper wires. Unlike ordinary passive cables that can be used at lower data rates, the unprecedented speed of the new Thunderbolt™ technology places unique demands on the physical transmission media. The GN2033 provides the sophisticated signal boosting and detection functions required to transfer high-speed data without errors across inexpensive Thunderbolt™ copper cables."
Original image courtesy of iFixit
The cable's $50 price may be justified, but it's also a further reminder of why Thunderbolt may follow FireWire's path into obsolescence. Apple is the only company currently selling Thunderbolt cables. Sony's recently announced Vaio Z will use Thunderbolt controllers but won't be compatible with any other Thunderbolt peripherals.
Promise Technology's interface comparison
The Vaio Z uses a proprietary modified USB 3 optical port. Said port is used to connect to the Vaio Z's Power Media Dock; Sony describes the functionality thusly:
Featuring high-speed I/O data transfer based on the architecture codenamed ‘Light Peak’, Power Media Dock boosts graphics performance while adding numerous extra connectivity options... With Power Media Dock added, VAIO Z can manage up to four displays (including the notebook screen) via HDMI™ and/or VGA output ports. In this configuration, VAIO Z makes a compelling choice for design, finance and science professionals who need to work across several screens simultaneouslySony's decision to adopt Thunderbolt for one particular purpose isn't a design win for the standard as a whole. There are other Thunderbolt-compatible peripherals on the way and Sony's decision to use Light Peak as an external GPU interface could be the beginning of a trend. We're admittedly dubious on this last point. Gamers have long clamored for upgradeable mobile video cards and/or external graphics solutions, but shipping products have been few and far between. Fujitu's AH530 GFX was supposed to deliver an external GPU last year, but there's precious little evidence the company ever shipped units in volume. Similarly, the MXM standard theoretically allows for video card upgrades, but upgradeable systems are few and far between.
At this point, there's little reason to think Thunderbolt's strengths will be sufficient to establish it outside of a narrow market range. Add-on cards probably will exist at some point to enable high-end PC workstations to take advantage of the standard, but its mass-market appeal looks pretty thin.