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USB 3.0: Your Questions Answered

  • Category: Buying Guides

USB 3.0 has been making headway lately, both in the tech media and from some hardware manufacturers, but what is this new USB 3.0 standard? This USB 3.0 guide will break it down and answer some commonly asked questions about USB 3.0's usability, backwards compatibility, speed, and more.

What is USB 3.0?

USB 3.0 is the next major revision of the Universal Serial Bus, which was originally formed in 1996 by a group of companies led by Intel to create a simple connection between computers and peripherals. USB 2.0, the current standard, has been the de facto standard for years now and more than 6 billion USB 2.0 devices have been sold.

USB 3.0 was first shown off in 2007 when Intel demonstrated what they called "SuperSpeed USB". Since then they have been working on improving and unifying the USB 3.0 standard so when peripheral and computer makers receive the USB 3.0 specs, they will work universally.

USB 3.0 promises the following enhancements:

  • Higher transfer speeds up to 4.8 Gbps
  • Full-duplex data transfers (allows for simultaneous back-and-forth data transfer)
  • Increased bus power to allow for more power supply to devices
  • New power management features
  • New connectors and cables, but they are backwards compatible with USB 2.0 standards

How does USB 3.0 gain these new features?

USB 2.0 currently uses only four wires (power, ground, 2 for data) while USB 3.0 adds four more wires for receive and transmitting data. This means that USB 3.0 will be able to simultaneously send and receive data where USB 2.0 cannot. This means a ten-fold increase in bandwidth in itself from USB 2.0's 480 Mbps max transfer rate.

What does the new power management features mean for me?

USB 2.0 has been known for not being able to provide enough power for power-hungry devices, which is why some peripheral require a power connection in addition to the USB connection. USB 3.0 provides up to 50% more power for simple devices (up to 150 mA from 100 mA) and 80% more power (up to 900 mA) for more advanced devices. This means many things for devices, such as faster charging, less need for a power connection, etc. There is a new B connection for USB 3.0 that is powered, which can provide up to 1000 mA to extremely power-hungry devices because they contain an extra two power contacts in the connector.

Are the new connectors backwards-compatible?

Yes. Existing USB 2.0 peripherals will continue to work with 3.0 ports and vice-versa. However, plugging in a USB 2.0 device into a 3.0 host will only be able to achieve the maximum speed and power allowed by the 2.0 standard. In other words, the speed and power allowed will be limited by the slowest standard connected.

USB 3.0 connectors are longer, however, to allow them to reach the extra set of contacts located deeper on USB 3.0 ports. This won't affect backwards compatibility because plugging into a USB 2.0 port just means those extra set of contacts won't be connected, but the essential contacts will be connected. Therefore, plugging in a USB 3.0 cable into a 3.0 port will allow for the connectors in the far back that provide that extra speed and power boost will come in contact. You can see these added 3.0 contacts in the picture above.

 

In the pictures above, you'll notice that the left and center picture look very similar as those are exactly the same connectors as USB 2.0, but with longer connectors and a few extra contacts. These will fit into existing 2.0 ports and peripherals. The picture on the right is of the new B connector, which is new to USB 3.0 and provides that extra power output increase we discussed earlier. Since this is a new connector, this will not work with any USB 2.0 devices simply because it won't fit.

You might also notice the cables themselves are thicker. This is due to the extra four wires located inside the USB 3.0 cable. The new cable thickness is very similar to the thickness of an Ethernet networking cable.

When will new USB 3.0 compatible devices come to the market?

It will be at least a few more years before USB 3.0 devices will become mainstream, but expect to see high-end devices, particularly high-bandwidth devices, coming out with USB 3.0 during the second half of 2010. This is mainly due to cost considerations and demand, which again will restrict USB 3.0 adoption to higher-end products in the beginning.

The first devices that will probably be USB 3.0 compatible first are external storage devices mainly due to the transfer speed increase, with printers, scanners to be the very last to be 3.0 compatible.

How will I get USB 3.0 ports on my computer?

There are many different ways. The mainstream way is through buying a new computer after USB 3.0 has become more widespread. A new computer will come with USB 3.0 ports on the motherboard, but this won't be until probably the second half of 2010.

If you don't want to buy a new computer, you can upgrade an existing computer one of two ways. The more costly way is to upgrade your motherboard to one with 3.0 ports on it, but this can potentially mean buying a new CPU, RAM, etc. Some motherboards are already available with USB 3.0 ports on them. One such board is the Asus line of P7P55D-E, which costs around $220. Gigabyte also has a few motherboards out (P55A series) with 3.0 spec included in a similar price range.

The easier and less costly way to upgrade is by buying a PCI Express card that will have 2 to 4 USB 3.0 ports on the back of it. These will cost less at around $30-60 once they go on sale.

Windows 7 does not include any USB 3.0 drivers as of yet, but Microsoft has said they will be included in a future update. No word yet on availability of drivers for Windows XP or Vista.

Final Thoughts

While USB 3.0 is a definite improvement over USB 2.0, in terms of both speed and power management, 3.0 won't come into the spotlight for awhile yet. More advanced users will probably be able to upgrade their systems or buy higher-end computers with 3.0 ports around the second half of 2010, but 3.0 won't become widespread until 2011. Bottom line: Don't worry about upgrading to USB 3.0 yet and don't hold off buying a new computer just to wait for USB 3.0 to become available on new computers, because that won't be for awhile yet.