Original URL: http://www.theregister.co.uk/2011/06/30/inside_apple_thunderbolt_cable/

Pricey Apple Thunderbolt cable inner chippery exposed

40 quid for wires... and 12 chips

By Tony Smith

Posted in Hardware, 30th June 2011 12:02 GMT

Want to know why Apple is charging £39 - $50 in the US - for its Thunderbolt cable?

For once it's not entirely the company's price-high-for-fanboys policy - the cable is an active transmitter.

Apple's Thunderbolt cable

Apple's Thunderbolt cable: on the outside...

The kit disassemblers at iFixit.com have found that the cable, which connects Macs to peripherals using Intel's new high-speed - two independent channels of 10Gb/s each - bus, contains rather more chippery than you'd see in your average cord.

Inside Apple's Thunderbolt cable
Inside Apple's Thunderbolt cable

...and on the inside
Source: iFixit.com

There are six chips at either end of the cable, but the grunt work is done by two of chip-maker Gennum's cable-oriented GN2033 Thunderbolt transceivers.

Essentially, these boys and the supporting parts ensure the 2m of wiring - 3m is the max - in between don't attenuate the signal so far that the data transfer speed plunges.

All this means that the cable is also powered - for the chips, if not the external device. Thunderbolt muxes PCI Express bus data and DisplayPort traffic then separates them out at the other end. ®