The universal standard Thunderbolt can replace all current
PC ports and is four times faster than USB 3.0. Macs already have it; PCs will
get in only in 2012
PC
users have dreamed of this for years: fewer cables on their devices, and higher
transfer speeds for all data. This could become reality with Thunderbolt.
Instead of fidgeting around with different cables and standards for HDMI, VGA,
Display Port, DVI, eSATA, USB or FireWire, the computer user will be able to
connect just one Thunderbolt cable. And in addition, Thunderbolt also achieves
much higher data transfer rates than the USB 3.0.
Thunderbolt is coming to Windows
Thunderbolt has only available in around a dozen
devices till now, since Apple has been the only computer maker using it. But PC
firms are following suit and even Windows computers will come with Thunderbolt
in 2012. Large corporations like Acer and Asus want to first build Thunderbolt
into their Ultrabooks. In order to successfully launch them in the market next
year, the work on Thunderbolt has already been going on for a long time behind
the scenes. Intel first introduced the technology in 2009 under the codename
Light Peak. The idea then was of an interface that would work between computers,
monitors, peripherals and entertainment electronics. As the name suggests,
Intel had planned for an optical transmission medium, but in the official
introduction of the Thunderbolt standard at the beginning of 2011, a
traditional electronic process with copper wires was used because of cost
considerations. However, one of the strengths of Thunderbolt is that the
optical transfer option has not been shelved entirely. A layer has explicitly
been specified in the protocol for electrical and/or optical transfer. The
transportation medium is defined as an independent layer in the stack. Intel
has already communicated that a second generation of Thunderbolt devices will
use the optical transfer technology. This will require fiberglass cables, but
all controllers and connections that are already available with the first
generation devices should also work with optical cables without any problems.
One huge advantage of the change will be that cables up to 10 meters long will
be possible, instead of the 3-meter maximum in the current specification.
Flexible distribution of data streams
What is unique about Thunderbolt is that it uses
parallel data channels that work in both directions simultaneously. The full bandwidth
capacity is thus available in both directions, and there is no division of capacity
between upstream and downstream devices. The two bidirectional channels can
transfer a total of 10 GB per second each. Since you can connect up to six
devices on one cable, the speed will be divided if several devices
simultaneously send data to and fro along the same channels. The first
benchmarks from the CIS(Cyber info Scripter) Test Center show that this maximum
rating has not been achieved in reality. We could coax a superb transfer rate
of 825 MBps from a Promise hard disk array. This was still disappointing,
considering the maximum theoretical rate of 1,250 MBps. As it turns out, other
components are the limiting factor here, like for example the RAID controller,
which causes bottlenecks. Thunderbolt has even more potential though. In 2015,
Intel plans to push through with 50 GBps per channel, and then in 2019 up to
100 GBps. A look at the transfer protocol architecture shows
that Thunderbolt uses Display Port and PCIe, two
existing and popular standards, as the basis for its own metaprotocol. For
computers, connected devices and installed programs, it appears as though known
protocols are being used. The Thunderbolt protocol stack primarily ensures that
the data packed together is transferred efficiently and lands at the correct
spot. Besides traffic routing, Thunderbolt also offers one or more other
user-friendly functions. Hot Plugging, the concept of connecting and
disconnecting devices while they are running, is something that we now take for
granted. Still, a lot of work is required in the protocol stack to allow for
this kind of user behavior. The heart of the Thunderbolt protocol is the
transport layer, which ensures that the connected devices are running synchronously.
Another advantage of Thunderbolt cables is that they can also be used to
provide power to connected devices. Intel specifies up to 10 Watts per Thunderbolt
cable.
 |
Speedy socket for everything The expensive cables have chips
embedded at either end to
actively manage data traffic.
|
Cheaper with new chips
What momentarily overshadows the excellent impression
made by Thunderbolt is that devices and even cables are expensive. Although
they are mechanically identical to existing Display Port cables, Thunderbolt
cable ends have active circuitry which makes their production extremely
expensive. Hence, Apple sells a 2-meter long Thunderbolt cable for a steep US
$50. First-generation Thunderbolt controller chips are acknowledged to be too
expensive in comparison to other technologies, but that situation will improve
over time. With the next generation of Thunderbolt controllers, Intel will
offer a standard model (codenamed Cactus Ridge) as well as a low end version
(Port Ridge). At 5 x 6 mm, it measures just one third of its more expensive
sibling and will represent the breakthrough for Thunderbolt technology in
reasonably priced computers.