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USB 3.0 Ups Peripheral Bandwidth

USB: A Success Story

It took quite a while for USB 2.0, the second-generation Universal Serial Bus specification, to become as popular as it is today. Intel had launched USB back in 1996 as a replacement for serial RS-232 and parallel 25-pin connects. And although the benefits typically speak for themselves, it required broad support at a platform level to be considered successful.

Even though Intel implemented USB support in its 440FX chipset for the Pentium Pro and Pentium II, it wasn't destined for broad adoption, due to missing software support in Microsoft's Windows 95 and Windows NT 4.0 operating systems. Moreover, there were only few USB devices available back then, making the launch even more difficult. USB 1.0, at its 12 Mbit/s data rate, clearly started as a niche interface.

Useless or Universal?

Many users scoffed at the Universal Serial Bus when Intel updated the specification in 1998. Version 1.1 introduced interrupt transfers, which are important for HID devices (Human Interface Device, such as keyboards and mice). However, USB 1.1 did not enable faster transfer speeds, meaning that the throughput remained 1.5 Mbit/s at low-speed link mode and 12 Mbit/s at full speed.

The Need for Speed: USB 2.0

Two more years later, in 2000, the USB specification received another update. This time it was USB 2.0, which brought a significant increase in bandwidth, as it offered 40x more bandwidth and peak gross throughput of 480 MB/s in high speed more. Fortunately, USB 2.0 was still compatible with USB 1.1, which was important to support first generation USB thumb drives, which initially were all based on the 12 Mbit/s USB 1.1. standard.

True USB 2.0 devices hit the mainstream in 2002, which finally saw the interface come into its own. The bandwidth of 480 Mbit/s wasn’t only fast enough for thumb drives, but also for external storage devices, MP3 players, smart phones, and digital cameras, which require moving lots of data.

Since its breakthrough, USB 2.0 has effectively replaced serial and parallel interfaces--a fact that is most noticable when you look at a sample of the latest motherboards. Only few products still come with parallel or serial interfaces, as these are no longer necessary for consumers products, and retain only a small presence in server environments and industrial computing.

The success story of USB will continue soon, as USB 3.0 is prepared for mainstream consumption.