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HOME REVIEWS CONTACT ABOUT March 21, 2009
SuperSpeed USB 3.0
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One of
the best enhancements to computers in the last 10 years has been the addition
of Universal Serial Bus (USB) ports. Technologies
like Firewire are terrific, but the popularity of USB is unprecedented. USB is the most versatile and popular
computer interconnect ever. To date,
over 6 billion USB ports have been sold.
If you purchase a desktop computer, USB is probably used for the mouse,
keyboard, and printer connections. In
addition, many general purpose connections like a thumb drive use the USB
port. One of the best attributes of USB
is that the connection can be made without restarting the computer.
USB, in
its current format is known as USB 2.0.
2.0 has been the standard since 2002.
USB 2.0 has a data transfer rate limit of 480 Mb/sec. That rate is good for most applications, but
is wanting for applications like video.
"The
future of computing and consumer devices is increasingly visual and bandwidth
intensive. Lifestyles filled with HD media and digital audio demand quick and
universal data transfer. USB 3.0 is an answer to the future bandwidth need of
the PC platform.” Phil Eisler,
President of the chipset business unit at Advanced Micro Devices.
The new
specification is predictably called USB 3.0 (also called "SuperSpeed
USB"). USB 3.0 is capable of data
transfer rtes of 4.8 Gb/sec (10X faster than USB 2.0). USB 3.0 is a version of
USB that is similar to PCIe Gen2 signal techniques, but with a connector
cosmetically similar to the USB connector to which we are accustomed. A 30 GB HDTV movie that takes about 15
minutes to transfer with USB 2.0, will take less than 90 seconds with USB 3.0. The connectors were shown to the general
public for the first time at last year’s CES (Consumer's Electronics
Show). Equipment designed to meet USB
3.0 will be backward compatible with USB 2.0 hardware, but when a USB 3.0
device is connected to a USB 2.0 device, the performance will be at USB 2.0
performance levels.
USB
3.0
USB 3.0
has more pins than USB 2.0 (9 instead of 4), but the connector remains
compatible with the old form factor.
Pins 1-4 are called the "USB 2.0 Pins" and Pins 5-9 are
referred to as the "SuperSpeed pins”.
When interconnecting a USB 2.0 connector with a USB 3.0 connector, pins
5-9 will be open. There are two
mechanical configurations for USB 3.0.
"Standard A" connectors are fully compatible with USB 2.0. USB
3.0 devices are not required to be compatible with USB 1.1 and older
devices. A color coding (Blue Pantone
300C) of the USB 3.0 connector is planned.
Applications
Synopsys
has prototyped an HDTV transmission system based on USB 3.0. The company has demonstrated transmission of
non-compressed 1080p at 30fps HDTV via USB 3.0.
Apple
has anticipated USB 3.0 with built-in capabilities with the iPhone. There is firmware on the iPhone to facilitate
connecting your laptop computer to the phone via a USB 3.0 connection. The iPhone can then be used as wireless
modem for the computer. Apple says that
this capability exists with the iPhone 3.0 OS, but details still need to be
negotiated with carriers.
At least
one laptop manufacturer is already integrating the new connector into their
system. The latest versions of the Asus M50 laptop come equipped with 2 ports
that are ready for the additional contacts.
Asus has framed their system for USB 3.0, but the full system is not yet
in place.
Consumer
products utilizing USB 3.0 should become available later this year (2009), and
in general use in 2010. The first products to market will probably be flash
drives, digital music players, and digital cameras. Initially there will be a price premium for
the new technology. In this case, it is
justified, since it will be a significant challenge for the manufacturer to
meet the specification requirements.
Appendix 1: Data Rates of Competing Interconnects
|
Technology |
Data Rate (Mbps) |
|
USB 2.0 |
480 |
|
USB 3.0 |
4800 |
|
Firewire (FW400) |
400 |
|
Firewire (FW800) |
800 |
|
Serial ATA (SATA1) |
1500 |
|
Serial ATA (SATA2) |
3000 |
|
Serial ATA (SATA3) |
6000 |
|
SCSI 160 |
1280 |
|
Ultra SCSI 320 |
2560 |
|
Serial Attached SCSI (SAS) |
6000 |
|
HDMI 1.2 |
4950 |
|
HDMI 1.3 |
10200 |