Key to that rumoured 12-inch MacBook Air is the USB “Type-C” connector. Dong Ngo, CNet:
To quickly recap, apart from the fact that with Type-C there’s no need to worry about which side of the cable to plug in (it works either side up), it also packs the USB 3.1 standard, which comes with a top speed of 10Gbps, twice the current speed of USB 3.0.
It also includes support for displays and much higher-wattage power, which means that someday you will be able to plug one cable into your laptop to charge it and connect it to your big, desktop display. But, while 10 Gbps is no slouch, it’s just half the speed of a Thunderbolt connection, which is 10 Gbps in both directions simultaneously, or 20 Gbps with Thunderbolt 2. That kind of bandwidth can be largely eaten up by using a high-resolution display1 and a backup hard drive.
But USB Type-C has a couple of advantages over Thunderbolt. First, it’s reversible, like any good connector.2 Second, it’s actually going to be adopted on a much more mainstream basis, and compatible peripherals should be less expensive and more plentiful.
My Thunderbolt Display, for example, is 2,560 x 1,440 pixels, each with three subpixels at eight bits of depth, at 60 Hz, for a total bandwidth requirement of approximately 5.3 Gbps. ↩︎