Monday, June 4, 2012

Thunderbolt: II FireWire, Fibre Channel VIII or ePCIe or II? - II

To believe a majority dissatisfied on the forums, which lack most current Mac is USB 3. And most superfluous on the same Mac, this is the port Thunderbolt. Both interfaces are not the same vocation, but the absence of a utility and yet on the other have reconciled. The fee for professionals rather adds to the resentment of a population which, in fact, has yet to use a port to such performance. But is it simply a matter of performance?

For USB 3, the matter should be resolved with the first de facto Ivy Bridge chipsets. It is difficult to restrain fun Apple USB on its new machines ... The lack of USB 3, while the interface is present on the market for over a year, goes to a desire for Apple to require the user to wait until the Thunderbolt suddenly downgraded to a competitor of the 3 USB, has won market share. There's probably true, but we must not forget the primary purpose of the Thunderbolt on the machine man in the World: the replacement of the DVI cable. How many users "injured" at least use the FireWire on a regular basis? The fact is that in many cases the need is not proven: large consumers have adopted the FireWire drives since longtemps. And if the Thunderbolt was also essential, the market would flourish of FireWire 800.

While Apple seems to engage in this horrible conspiracy, Intel, the leading developer of USB 3 as the Thunderbolt, is quick to adopt the new kid on the platform called "Ultrabook" designed to exploit the seam of MacBook Air. The size of the connectors is obviously paramount to refine up to these machines, and the Thunderbolt is openly presented as the solution to make their extensions. And to specify the depth modestly on its website: "The Thunderbolt technology is complementary to other technologies I / O Intel continues to promote".

Experience FireWire

Technically, Thunderbolt and USB do not play in the same court. And in practice, we could not live without the USB interface is as simple as that. This is a hitch sized assuming a duel between the two. In fact, this is not the USB should be compared the Thunderbolt, but the FireWire. Not only the two interfaces have much in common, but they seem destined to start their careers in very similar ways. In its infancy, despite the obvious technical advantages, FireWire has never claimed to rival the USB in terms of market. With a more expensive controller, it was reserved for the machines at least mid-range, and especially infancy. In still uses the same time, reigned supreme on Wintel computers, and was adopting "a" port everything: the USB. Ironically, although timidly on the market since 1996, this format had to wait for the gamble of the iMac and the arrival of devices to truly supplant the old PC interfaces. The USB was so quiet: it took several more years to appear on some PCs 4-pin FireWire ports. Derived version called Sony i.LINK, they lacked power and dedicated to video use.

Yet all was not running round always between Intel and Microsoft. For the software giant, the USB was not up to Apple's interface, which won all the votes in the professional field. Microsoft opened the same network over FireWire, an application prior incongruous and now abandoned by Windows, but that made sense on this interface at 400 Mb / s, at a time when the built-in Ethernet in the machines peaked at 100 Mb / s. equivalent of Thunderbolt is tempting, but has no reason to arrive before the optical cables, a TCP / IP limited to 2 meters cable length of current is necessarily reduced to very few uses.

More upscale, focusing on quality rather than quantity, FireWire has suffered a change in connector midterm. For the general public, the mass was over: it was too complicated. Furthermore, the roadmap of FireWire has never been observed: the 400 and 800 Mb / s versions were to succeed in 1600 and 3200 Mb / s. However, this port has remained inescapable. It has long been the fastest in practice, and the flow of a FireWire 800 is quite topical. Moreover, his notion of "guaranteed rate" makes it suitable for applications in near real time, especially the video until a given threshold. As a bonus, its electrical power has allowed the appearance of the first generation of self-powered devices (hard drives and recorders), without the constraint of the dual connection (data cable and power cable) which has long been known with the USB. At final, FireWire is certainly one of the most successful Apple technologies. No doubt he would have been supplanted by USB 2 if it was not imposed in the audiovisual sector. He was the only interface used on virtually the entire range of materials, the general public to professional, and this is undoubtedly what earned him make a very honorable career.

Impossible to say whether the Thunderbolt will succeed him on this ground, but the facts are there: the new interface has everything you need to replace FireWire, and even other interfaces commonly used in digital broadcasting. Among the dozen companies that already produce equipment based on the Thunderbolt, third belongs exclusively to industry audiovisual.

Fiber Channel, the real inspiration

Apart from very specific applications of computers, it is precisely Audiovisual which is the main prescriber in terms of media and high-capacity interfaces. This demanding market has adopted fifteen years ago a very advanced technology: Fibre Channel, which is written in English. In addition to its disproportionate cost, the complex nature of Fibre Channel has helped keep it in a niche market. Indeed difficult to determine which club it belongs: a bound volume in Fibre Channel to a computer is a good device. But let him come to get away and go through a network more serious and it is closer to a NAS. Yes, but an NAS that uses a SCSI protocol originally intended for devices. Yes, but you can use the IP protocol, so it's network. Yes, but then we do not talk over the network, but the SAN (storage area network). Yes, but ... Not easy. A point to remember: the Fibre Channel has been more successful than FireWire. He found and expanded its market, and he followed his roadmap: in fifteen years, its rate was multiplied by sixteen!


"And in addition the cables are too expensive!" do we hear today against the Thunderbolt. In comparison, why USB, FireWire or Ethernet is it economic? Simply because we do not have to cheat to make pass information: the cables are below the usual physical constraints, without requiring a close monitoring of transmissions onboard electronics.

The Fibre Channel already required such controls flows of 1 to 4 Gb / s. With 10 Gb / s full-duplex, dual channel and a smaller section, the Thunderbolt has more need than ever. Without going into too many technical terms, we can say that the physical characteristics of a cable (length, cross section and electrical resistance, in particular) have a direct influence on the quality of the signal flowing through it. Beyond a threshold often located toward the 5 Gb / s (theoretical speed of USB 3), we routinely use active cables, which are more simple cable assemblies and receptacles of a specific format. Electronics is then housed in the envelope taken to adapt the signal to noise characteristics of cable. Other problem: electronic heater. Therefore quality components, to avoid the fiascos of the first AirPort Express, or MacBook Pro with NVIDIA GeForce 8600 GT. Fleas Gennum GN2033 identified by iFixit, who sacrificed an Apple cable for more, are used according to the manufacturer for computers as well as for devices, but specifically for anything related to the near-real time. Ie clusters, Thunderbolt cables, FireWire and USB, as well as extensions that Thunderbolt has not yet seen on the market.

Copper: the false controversy

The choice of copper for the first version of the Thunderbolt has triggered a near-scandal among the neophytes attracted by the fiber. Ironically, the world's well-established Fibre Channel, no one cares whether the cable contains fiber or copper: the flow is there, and that's all that matters. A short distance (2-3 m), copper is used, and it works very well.

In the case of Thunderbolt, copper has an advantage over the same fiber is its ability to power a device. It now delivers 10 W of copper cable, against 45 W for FireWire and USB 2.5 for (9 W version 3). Given the potential of mobile Thunderbolt, self-feeding remains attractive, if only for a hub close to the computer, which would connect to multiple devices further away. As Fibre Channel, the Thunderbolt of fiber will increase the scope of the interface, but unless Apple unexpected breakthrough, it will lose its power capacity.

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