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.
This is because the 480Mbps (60MB/s) is for both directions AT THE SAME TIME.
If your copying data from 1 USB device to another, this is helpful, but the fact still remains the transfer rate between the PC and either of the drives is still going to be limited to 30MB/s
I would venture to guess that the 4.8Gbps transfer rate in USB 3.0 will be the same and therefore a file copy to/from a USB3 HDD will be limited to around 300MB/s. While this sounds great, and will likely satiate the needs of the traditional HDD market, this is basically the same speed as SATA 3Gbps that has been on the market for a few years now and will soon be replaced by SATA 6 Gbps in the next 12 months.
I have both intel and AMD CPU/Chipsets. And noticed this at some of my clients offices as well.
- ALL the intel systems required two USB connectors to power a 2.5" HD.
- The AMD systems (32bit, 64bit single / dual cores) did not. A single cable works fine.
The other issue... performance.
When backing up Gigabytes of info... backing up about 170GB of data with an AMD64 system takes about 2hrs. With an intel Q6600/P35 (and the other Core2 systems)it takes about 5 hours! Same Ext. USB drive. It sucks... nobody has explained why this happens.