USB 3.0: Coming to a PC near you

By Jay Dougherty Apr 5, 2010, 12:51 GMT

Washington - USB 3.0 might not be the sole reason that you run out and buy your next PC. But it will be a nice incentive. The successor to USB 2.0 - currently the world's most popular peripheral connectivity standard - USB 3.0 is faster and more versatile than USB 2.0. And it's beginning to show up now. Here's what's in store.

--- Speed

Marketed as 'SuperSpeed USB,' the new USB 3.0 standard is not just fast. It's very fast. Able to pump data at 5 Gigabits per second (Gb/s), it outperforms the Serial ATA interface that's used to connect most hard drives to computer systems today. That means it's more than capable of allowing you to get the maximum data transfer rate from today's hard drives - even from today's solid state hard drives.

USB 2.0, by comparison, moves data at a comparatively slow 480 Megabits per second (Mb/s). That makes USB 3.0 about 10 times faster than USB 2.0, at least on paper. In practice, early adopters of USB 3.0 gear reports data transfer rates that are closer to 3 times faster than USB 2.0. Still, that's a hefty increase - and enough to make those who regularly transfer large amounts of data think seriously about upgrading.

Perhaps even more exciting than the sheer performance improvements of USB 3.0 over USB 2.0 and other connectivity standards is that fact that USB 3.0 can operate in what's known as 'full duplex,' or bi-directional, mode: it can receive instructions or data at the same time that it sends them. USB 2.0 cannot. That capability will further enhance USB 3.0's usefulness, especially with devices that both send and receive a lot of data, such as audio interfaces.

--- Compatibility

The USB 3.0 standard is fully backward compatible, so your existing USB devices will work when plugged into USB 3.0 ports. Similarly, USB 3.0 devices will still work when plugged into an older USB 2.0 port, but you won't get the advantages of USB 3.0 unless both port and device are built to the USB 3.0 specification. And you either have to have USB 3.0 support in your operating system or install additional drivers to provide support. So far, Windows Vista and Windows 7 support USB 3.0 natively. Apple is not on board yet.

The USB 3.0 plug itself looks a bit different than the USB 2.0 plug. Instead of being completely flat, the newer plug is crimped in the middle. The USB 3.0 cable contains four more wires than the USB 2.0 cable. The extra wires are used in part to achieve the new standard's bi-directionality. Because of the different cable, you will not be able to fit a USB 3.0 cable into a USB 2.0 device. Also, to get the maximum throughput from a USB 3.0 device, you'll need to ensure that your USB cable is no longer than nine feet.

--- Additional features

USB 3.0 is a big improvement in other ways, as well. Chief among them is awareness of power managements schemes. The new USB supports idle, sleep, and suspend modes, ensuring that your peripherals will power down and wake back up when your computer does. In addition, can deliver 50 per cent more power to connected devices than USB 2.0 does. That means you'll be able to dispense with the separate power brick for a greater number of devices, since the USB 3.0 cable itself can both supply the power the unit needs and take care of two-way data transfer.

--- How can you get it?

For desktop users who don't want to buy a new machine with USB 3.0 built in, USB 3.0 add-in cards are now available. These cards are designed to be plugged into a free PCI Express slot on your machine's motherboard. You can find two-port cards today for anywhere from 35 to 50 dollars.

Notebook users, likewise, can turn to SuperSpeed USB 3.0 ExpressCard add-ins. These, too, typically give you two USB 3.0 ports in an existing machine, and they retail for about the same price as add-in cards for PCs. The most likely use for these, currently, is with external hard drive enclosures that support USB 3.0.

The add-on card for existing PCs is not a big deal - once installed, the ports show up just like other ports in your computer. For notebook users, though, adding an ExpressCard means having an extra device protruding from the case.

Notebook makers are finally beginning to include USB 3.0 functionality into their machines, although not all big manufacturers have USB 3.0-enabled models on the market. Currently, HP, Asus, and Lenovo offer models with USB 3.0 built in. Now that the new connectivity standard is becoming widely available, expect all other notebook makers to follow suit shortly.