Exclusive content: The Evolution of USB
Before PZ Tech go for a long break next week, I would like to present to you an article written by PZ Tech guest writer, Mr Teo Tat Lee.Mr Teo Tat Lee is a Senior Lecturer in the Department of Electronics & Computer Engineering, Ngee Ann Polytechnic and for his first article, he is touching on the upcoming USB 3.0 standard and how it will affect the way we store our data in terms of hardware and speed.
The evolution of USB – From version 1 to version 3
By Teo Tat Lee, 16th May 2009
Brief history
On the 15th January 1996 , 7 companies jointly developed and announced USB Specification revision 1 under the industry group known as USB-IF (USB Implementers Forum, Inc), this was quickly followed by a minor update to revision 1.1 on 23rd September 1998.
After another short lapse of about 1-and-a-half year, a slightly different composition of 7 companies released USB version 2.0 on 27th April 2000 defining a new data transfer rate named ‘high speed’, raising the top UBS data transfer rate from 12 million bits per sec to 480 million bits per sec.
In the years that follow the release of version 2 specifications, many USB peripherals were developed.
However, with devices like external USB 2.5” drives now hit 500 GB, and transferring of giga-bytes of data becomes common, USB 2.0 speed does not appear to be fast anymore!
With the availability of eSATA interface in the last few years, eSATA has become a potential replacement interface to supersede the ubiquitous USB interface for external drives! However, after years of development in secret, USB-IF announced the completion of the USB 3.0 specification on 17th November 2008, raising the top data transfer rate 10 times and naming this new rate “Super Speed”!
It is now up to the market to decide the dominant next generation interface for external drive to be either the eSATA or USB 3.0! One key factor deciding the outcome a couple of years from now would depend on the products developers as well as the levels of support provided by the Operating System! USB 3.0 peripherals could take off if the next version of Windows Operating System supports it the way it does with the version 2 peripherals!
The term giga here refers to 109
What other changes are there in USB 3.0?
Besides the obvious new speed, the physical connector and cabling are changed! The original USB version-2 connector and cabling will not support version 3.0 peripherals!
Behind the scene, the Bus protocols are also changed!
So, it will take a whole lot of new support at all levels, from device driver development, USB hub development, to built-in Operating System supports to bring the version 3 products to mainstream market!
Below is an abstract of the new features from the specification:
Note: In most write-ups we find on the Internet, writers refer to USB speeds as 12 megabits per sec and 480 megabits per sec etc. These are really base 10 numbers. I.e. 12 megabits per sec does not mean 12 x 220 bits per sec but refers to 12 x 106 bits per sec. In this note, I have used the term million instead to stress that we are talking about 106 multiplier, not 220 multiplier!
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