| How fast is USB 2.0? |
USB
2.0 has a raw data rate at 480Mbps, and it is rated 40 times faster than its
predecessor interface, USB 1.1, which tops at 12Mbps. Originally, USB 2.0 was
intended to go only as fast as 240Mbps |
| How will consumers benefit from USB 2.0? |
With speed 40 times more than that of USB 1.1, USB 2.0 broaden the range of
external peripherals that can be used on a computer. Even with multiple
high-speed peripherals connected to a USB 2.0 bus, the system will less likely
to hit the bandwidth bottleneck. The new specification also inherits the current
USB’s Plug and Play and hot-swapping capability as well as providing backward
compatibility for USB 1.1 hardware, allowing existing user base to upgrade
seamlessly. |
| What are the differences between USB 2.0 and USB 1.1? |
Basically, USB 2.0 includes everything
that USB 1.1 offers and adds a high-speed mode, which runs at 480Mbps. USB 1.1
supports two speed modes: 1.5 and 12Mbps whereas USB 2.0 has three of them: 1.5,
12 and 480Mbps. USB 2.0 also uses the same USB 1.1 compliant cables to connect
high-speed devices. However, classic USB hubs will slow down USB 2.0 devices. In
addition, a USB 2.0 host controller is required to enable the high-speed
connection with a USB 2.0 device. |
| Will USB 2.0 replace USB 1.1? |
Not entirely, because many products such as generic keyboards, mice, joysticks
and audio speakers do not require the faster speed of the new USB 2.0
technology. Only bandwidth-hungry devices, such as webcams and high-capacity
storage systems, will need all the speed. However, next-generation systems will
come with USB 2 ports rather than USB 1.1. |
| Will USB 1.1 devices run any faster on a USB 2.0 bus? |
No. However, the new USB 2.0 architecture allows more high-speed USB 1.1
devices, such as webcams, audio devices, to share the bandwidth. Developers need
to follow USB 2.0 spec in order to design higher speed peripherals that can take
advantage of the extra bandwidth. USB 1.1 devices still operate at 12Mbps at
full-speed and 1.5Mbps at low-speed on a USB 2.0 bus. Even though USB 1.1
devices won’t run any faster, they can work alongside of USB 2.0 devices on the
same bus. |
| What happen if a USB 2.0 device is plugged into a USB 1.1 system? |
The entire bus under the USB 1.1 root hub will slow to 12Mbps. The operating
system will probably notify the user about the sub-optimal configuration and
recommend for a better course of action.<br>
If several USB 1.1 hubs are connected to a USB 2.0 bus, then each of the USB 1.1
hub will get a full 12Mbps bandwidth. |
| What do I need to use a USB 2.0 device? |
The requirement is similar to that of USB 1.1, but all components will have to
be USB 2.0 compliant. A successful USB 2.0 connection requires a USB 2.0 host
controller card, a USB 2.0 driver and a USB 2.0 peripheral |
| Will USB 2.0 arrive on mobile computers? |
Yes, but not in integrated solution on laptops. You will need a
USB 2.0 CardBus card. Orange Micro. is shipping USB 2.0 compliant 4-port CardBus
card. Eventually, notebook vendors will adapt to USB 2.0 technology, and we will
see USB 2.0 ports on laptops. This transition won't happen until 2002 at the
earliest. |
| Do USB 1.1 cables work with USB 2.0 devices? |
Ideally, yes. USB 2.0 architecture uses the same cables and connectors as USB
1.1 compliant products. Unfortunately, only 3 out of 11 cables on the market are
certified as USB 1.1 compliant. You may run into the cables that cause problems
connecting high-speed peripherals. To avoid negative user experience, most
vendors include USB 2.0 compliant cables with their USB 2 PCI cards and
peripherals. |
