Universal Serial Bus 2.0 (USB 2.0) Quick Tutorial

USB 2.0 is the latest USB standard, which increases the data transfer rate of the current USB standard of 12 Mbits/sec (1.5 MBytes/sec) up to 480Mbits/sec (or 60MBytes /sec). USB 2.0 is backward compatible with USB 1.0. Peripherals equipped with USB 2.0 can connect to any USB port. Likewise, peripherals equipped with USB 1.0 can also connect to any USB 2.0 port. To learn more about the benefits and the technical details of the USB or USB 2.0 technologies, please visit the following web sites: www.usb.org, http://developer.intel.com/technology/usb/, or read the FAQs below.

In order to achieve the fastest data throughput capability of the USB 2.0, both the peripheral device and the host controller (USB port on the computer) must be designed with USB 2.0 capabilities. Since most computers being used today are equipped only with USB 1.0, users will need to add a PCI USB 2.0 host controller to the desktop PC in order to have the USB 2.0 capability.

Since all Addonics External Storage devices are designed with the Addonics unique Universal Storage Interface BUS (USIB) connector, customers with USB 1.0 device can upgrade to USB 2.0 by switching to the Addonics USB 2.0 USIB interface cable. The Addonics USB 2.0 USIB interface cable requires no special driver under Windows 2000, Me or XP. The cable will automatically perform at 2.0 speed when it is connected to a USB 2.0 host controller. In addition, th cable is also designed to power all Addonics Pocket storage devices via USB connection when your computer supplies sufficient power to the USB port.

All Addonics USB products have been certified by USB-IF and are shipped with USB 2.0 USIB interface cable as standard.


 

Q. Can I connect the Addonics USB 2.0 storage device to a USB 1.0 port?
A. Yes, Addonics USB 2.0 device can connect to any USB ports.

Q. I have upgraded my Addonics drive with the Addonics USB 2.0 USIB interface cable. How come I did not notice any improvement in performance?
A. Check to make sure that your computer is equipped with USB 2.0 host controller. USB ports that come with computers today are all USB 1.0 design. You will need to add an USB 2.0 host controller to your computer in order to realize the improved performance of the Addonics USB 2.0 USIB interface cable.

Q. I have a USB 2.0 host controller in my computer, but I see no performance gain with my USB hard drive.
A. Make sure your USB hard drive is equipped with USB 2.0. A USB 1.0 peripheral can only perform at USB 1.0 speed even if it is connected through a USB 2.0 port.

Q. I have both the USB 2.0 host controller and the USB 2.0 USIB interface cable for my Addonics Pocket 4X CDRW. But I did not notice any gain in performance.
A. The maximum data transfer for a 4X CDRW is 600KBytes/sec. So the speed performance is limited by the 4X CDRW. USB 2.0 will show noticeable benefits only for fast devices such as hard drives and drives that are at least 8X or faster.

Q. I connect a USB 16X CDRW to the USB 2.0 host controller in my computer, how come I am getting a buffer under run at 16X?
A. Check to make sure your computer has at least a Pentium 3 CPU with 256K RAM. You need a fast CPU and enough memory to get the maximum performance of a fast 16X CDRW.

Q. I connect a USB 2.0 hard drive (an UDMA IDE hard drive) to a USB 2.0 host controller. But I do not get the full 60 Mbytes/sec data transfer?
A. The 60 MBytes/sec is the raw speed of the USB 2.0 standard. But there is overhead in actual data transfer due to error correction, hand sake between the device and the controller, BUS latency plus other software hardware overhead. The maximum achievable throughput you get may only be 60% to 70% of the maximum depending on your system hardware and the applications you are running.