I was quite impressed when I received an e-mail advising me that Western Digital are now offering a new drive called the My Book Thunderbolt Duo with an Intel Thunderbolt interface port with a supposed transfer rate of 10Gb/s or 10 Gigabits per second.
But all is not what it seems.
Unfortunate my initial enthusiasm was somewhat diminished by reading the fine print in the speed graphic.
The actual performance of the device is given in MB/s or Megabytes per second, not Gigabits, so some arithmetic has to be done. Eight bits to a byte leaves us with a maximum speed of 2000 Megabytes/s or 2Gb/s, way below the indicated throughput of either Firewire or Thunderbolt port.
In fairness to Western Digital, the fine print is there, you just have to work at finding the truth.
The 10Gb/s throughput of the Thunderbolt interface is actually supposed to be a combination of up to two HD video channels, and multiple data devices, on a single cable, not a single device. The transfer rates are based on the manufacturers specification, not the realities of the device in question.