Macbook Air has a half-speed Thunderbolt port

EXPENSIVE TOY MAKER Apple put a Thunderbolt port into the latest model of its Macbook Air range, but it will only be capable of half the speed of Thunderbolt ports on other Apple devices.

The Light Ridge Thunderbolt chip used on this year's Imac, Macbook Pro and Mac Mini has four Thunderbolt channels, capable of up to 80Gbits/s of total bandwidth, along with two Displayports.

The Eagle Ridge Thunderbolt chip, on the other hand, has only half the channels and a single Displayport. This will be used by the Macbook Air, according to Anandtech, making for somewhat disappointing performance.

The problem for Apple is that it was a bit of a necessity in terms of price and space. The Eagle Ridge chip is much cheaper than Light Ridge, and it's also significantly smaller, coming in normal and small form factor versions. This made using it instead of the Light Ridge chip in the smaller and cheaper Macbook Air almost mandatory.

In terms of performance, 40Gbits/s bandwidth over two channels is still pretty decent. It will also support a single Thunderbolt display, rather than the two that a Light Ridge machine can handle, but it's unlikely that Macbook Air users are going to want to use two displays anyway, particularly when they come with such hefty price tags as Apple's Thunderbolt displays.

Thunderbolt is Apple's answer to next-generation connections. It boasts double the speed of USB 3.0 5Gbits/s bandwidth, along with two channels, effectively providing 20Gbits/s of bidirectional bandwidth.

At the moment not many devices support Thunderbolt. There's the Thunderbolt display, three storage devices, two video capture devices, and three adaptors. This limited range of peripherals is one of the problems that plague some other high-speed ports, including USB 3.0, and until it's addressed it will make one of the features of Apple's Macbook laptop range just that little bit less advanced. µ