USB Hubs and Ports Explained
The USB standard has become the universal means of connection peripheral devices and equipment to the computer. Computers have either two or four USB port connectors. Each of these can support a large number of connections but to be able to attach more than two or four devices requires a multi-connection hub. There are many different types of hubs and this article seeks to explain some of the important considerations in selecting the best choice of hub for your system.
The USB bus system in computers was introduced in 1996 and has gone through a number of developments and enhancements. It started out as USB 1 which was very slow and had many bugs. Version 1.1 brought a higher bandwidth of 12 MBits/second. The latest version of 2.0 gives a bandwidth of 480MBits/second and is fully backward compatible with USB 1 and 1.1. Link to a table showing differences between USB speeds (http://www.usb-products.com/usb-speed.aspx)
Port Connections and Power
Multiple Chip Hubs
What this means in reality is that a multiple TT hub will provide much higher bandwidth per port when several devices are connected from one hub.
Maximum Performance and choice of Where to connect a device If you are after maximum performance for each of your USB 2 devices, each device should be plugged into its own USB port in the computer. Additional plug in cards can provide a vast number of USB ports for most needs. However, this situation might be going too far except for the most demanding of situations. Although several USB devices might be connected at the same time it is unlikely that they will all be in use together.
A useful compromise is to plug small bandwidth devices together into a single hub. These would include: mice; keyboard; Speakers; little used devices.
For devices that require a high bandwidth and are used often, direct connection in to a USB port is the best option. Devices would include: Flash memory drives; external disks; Web cams; Other frequently used devices.
If you don't have sufficient ports then either more ports should be added with a plug-in card or a good quality hub with multiple transaction translators should be used. The devices placed on the hub are those that are used less often. Those devices placed directly on the port are used most often.
Link to a selection flow chart that helps in selecting a hub (http://www.usb-products.com/USB-Hub-Selection.aspx)
USB hubs tend to clutter up the area with cable connections and power lead. These naturally go out of sight if possible or behind the monitor. For mobile computers, a small compact hub can be obtained. These may have there own wind-in or tidy away cables.
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Nigel Stephens heads an online business at http://www.usb-products.com supplying computer hardware products. Nigel's emphasis is in providing useful information so that consumers can make more informed choices.
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