Everything You Need to Know About USB 3.0, Plus First Spliced Cable Photos


No doubt you’re familiar with the Universal Serial Bus – we ranked it as our top PC innovation of all time . But what do you know about the next version of this ubiquitous interface? USB 2.0 (otherwise known as USB Hi-Speed) boosted the original 12Mbps data rate to 480Mmb/s over eight years ago, and now USB 3.0 (dubbed USB Superspeed) is set to multiply that bandwidth tenfold. Intel released the Extensible Host Controller Interface to hardware partners last week after some reported disputes with AMD and Nvidia (who, afraid Intel would have a jump start in incorporating the tech in chipsets, threatened to develop their own USB standard). But how does this affect you? We dug up some new information about USB 3.0, got our hands on the new connectors, and even took a look inside the new cables.

(Edit made to clarify xHCI release)

USB 3.0 will be backwards-compatible with USB 2.0

Like the upgrade from USB 1.1 to 2.0, the new 3.0 connectors and cables will be physically and functionally compatible with hardware from the older specs. Of course, you won’t be able to maximize your bandwidth unless you’re using a USB 3.0 cable with Superspeed devices and ports, but at least plugging a 3.0 cable into a 2.0 port won’t blow up your PC. The spec’s compatibility lies in the design of the new connectors. USB 2.0 cables worked off of four lines – a pair for in/out data transfer, one line for power, and the last for grounding. USB 3.0 adds five new lines (the cable is noticeably thicker), but the new contacts sit parallel to the old ones on a different plane, as opposed to being adjacent to them. This means you’ll be able to differentiate between 2.0 and 3.0 cables just by looking at the ends.

At first glance, the USB 3.0 connector looks just like the 2.0 design

The maximum speed of USB 3.0 is 4.8Gbps

It’s true: USB 3.0 SuperSpeed will be 10 times faster than the 480Mbps limit of the 2.0 spec. The example Intel likes to give out when talking about the new speed is that transferring a 27GB HD movie to your future media player will only take 70 seconds with USB 3.0, while it would take 15 minutes or more with 2.0. Keep in mind that you’re only going to be able to take advantage of this speed if your portable storage device can write data that quickly. Solid state devices will benefit most from the speed boost, while magnetic hard disks will be limited by their RPM and corresponding read/write speeds. Also, new Mass Storage Device drivers will have to be developed for Windows to take advantage of the spec.

The USB 3.0 A and B-side connectors

Uploads and downloads are kept on separate data lanes

Remember those five new lanes we mentioned earlier? With USB 3.0, two new lanes will be dedicated to transmit data, while another pair will handle receiving data. This not only accounts for the significant speed boost, but also allows USB 3.0 to both read and write at the same time from your portable storage device. In the old spec, the pair of lanes used for data transfer weren’t split between send and receive – they only could handle traffic in one direction. Bi-directional data transfer will be very useful for syncing up information on PDAs and storage backup.

The packed guts of a USB 3.0 cable -- note that the cable will be about as thick as a ethernet cable

USB 3.0 will charge more devices, quicker

Not only will USB 3.0 cables facilitate faster transfer speeds, but they’ll carry more power, too. The USB-IF recognizes the growing number of portable devices that charge via USB (cellphones, MP3 players, digital cameras), and have bumped the power output from about 100miliamps to 900 milliamps. That means not only will you be able to power more than 4 devices from a single hub, but the increase current will let you charge up heftier hardware as well.

USB 3.0 will be more power efficient

One of the mandates of the new spec is more efficient power-usage protocols. USB 3.0 abandons device polling in favor of a new interrupt-driven protocol, which means non-active or idle devices (which aren’t being charged by the USB port) won’t have their power drained by the host controller as it looks for active data traffic. Instead, the devices will send the host a signal to begin data transfer. This feature will also be backward compatible with USB 2.0 certified devices.

A look at the mini connector that'll connect to cell-phones and other portable devices

The spec that Intel released mid-last week is only 90% complete. Ravencraft says that they expect the spec to be finalized by Q4 of this year. Hardware partners are expected to have USB 3.0 controllers designed by mid 2009, and consumers won't see the first end products utilizing the spec until early 2010 (though a late Holiday 2009 push for new products isn't out of the question).

What about Wireless USB?

With the internet in a USB 3.0 frenzy (keep in mind we won’t see hardware for a year), the USB-IF’s other iniative – Certified Wireless USB – often gets lost in the shuffle. Wireless USB technology has largely stayed away from the spotlight since the 1.0 spec was first completed in 2005. It’s not surprising, since adoption from hardware markers has been slow – the Wireless USB promoter group has only certified 75 products, with only 45 of those actually consumer end products that you can find in stores. Belkin, Dell, IOGEAR, and Kensington are a few of the partners that have signed on board, releasing hubs that unfetter your existing USB devices.

At this week’s IDF, Intel will be releasing more information about the next Wireless USB spec, version 1.1. Here are the key updates to the new spec:

-    Support for NFC. Near Field Communication technology is a short-range, high-frequency spec while allows for wireless data transfers between devices up to 20cm apart. The 400kbps data rate of this tech obviously won’t do any heavy lifting, but instead will be used for proximity-based device association and connection establishment. One of the big pitfalls of the existing Wireless USB spec is that syncing up devices to a hub or host takes too long. NFC will allow devices to “swipe to connect,” similar to how new credit cards can register with cashiers just by brushing against a sensor.

-    Speed and power usage optimizations. Power is one of the big concerns for Wireless USB, since no one (not even Tesla!) has figured out a practical way to transmit power wirelessly. Wirelessly connected devices like speakers or monitors will still need an external power source, but battery-powered peripherals will be able to sit idle longer.

-    Ultra-wide band (UWB) support. Wireless USB already runs in the 3GHz frequency range, which allows it to theoretically transfer data at speeds of 480Mbps at 3 meters and 110Mbps at 10 meters. Bluetooth, in comparison, operates at 2.4Ghz. UWB support will boost the frequency of Wireless USB to the 6GHz and up range, which lays the groundwork for higher data rates and throughput in the future (though at the cost of range).

We also got a demo of Wireless USB in action, running natively on a Thinkpad X300 laptop. The Thinkpad synced up with a nearby Belkin dock station, which had audio and video jacks that were connected to speakers and a LCD display. A WMV file streamed high definition video and five-channel audio to the hub and recipient devices, and playback was pretty smooth (though interference did cut in occasionally).

Another dock station from Kensington demonstrated similar features, offered a DVI port for video in addition to Stereo audio and 5 USB 2.0 ports, and includes a transmitting dongle for non-wireless USB integrated systems. Video streaming took most of the bandwidth, and we noticed that wireless video was capped at 1680x1050 resolution. Still, the setup was impressive in that it gave the laptop more mobility. We could definitely imagine using our laptops in bed while streaming video and audio to devices across the room. The docking station is a little pricey at $230 – hopefully prices will drop as more products are released to market.

Look for more USB 3.0 and Wireless USB coverage this week as we hit up the Intel Developer’s Forum!

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