FireWire (S400) has a maximum theoretical throughput of 400 Mbps, yet Hi-Speed ​​USB with 480 Mbps lags behind in tests. Why? Everything depends on the implementation of the FireWire bus, which provides more reliable data transfer than USB.

USB can only handle one external device per port, which is why high-end PCs come with eight ports. Of course, you can use a USB hub to add ports, but the performance of such a solution can vary significantly.

With FireWire, the situation is completely different, since all devices connected in series form a logical chain (with links point-to-point), and the protocol also allows the use of physical branches. Thanks to this, it is possible to stretch sufficiently long chains. However, if it is necessary to remove an intermediate device, then the connection for all devices in the chain will have to be interrupted for a short time. But one feature of FireWire is unchanged - the sharing of available bandwidth between all devices.

FireWire is not going to stop at 400 Mbps. Back in May 2002, the IEEE 1394b standard was approved, which raises the transfer rate to 800 and 1600 Mbps (S800 and S1600).

FireWire - latest history

The first FireWire standard was released in 1995 under the name IEEE 1394. With transfer rates of up to 400 Mbps, this port (also called Sony's i.LINK or TI's Lynx) outperformed all known protocols at the time. In addition, the FireWire standard allowed connection to be started and terminated during operation ("hot plugging").

The 1394 standard is a bus protocol that can connect up to 63 devices. Unlike networks on coaxial cable or SCSI, FireWire devices can be connected not only in series, but also in branches. The cable does not need to be terminated with a resistor, and device addresses are distributed dynamically without any user intervention.

Recently, the FireWire standard has found its place among high-end motherboards. Texas Instruments, VIA, and others offer inexpensive FireWire controllers. In addition, despite the lower theoretical peak bandwidth compared to Hi-Speed ​​USB, the IEEE1394 standard in practice gives a slightly higher transfer rate and less processor load - provided high-quality FireWire chips are used.

This cable is also used to work with older FireWire devices connected to the 1394b controller.

The interface is based on six pins that go into two twisted pairs of wires for data transmission and two wires for power. This configuration allows you to supply voltage between 8 and 30V with current up to 1.5A.

The maximum cable length from one device to another is 4.5 meters at full speed. At the same time, a maximum of 17 devices can be connected directly to the chain. Closed chains and loops are not allowed. However, the most common configurations consist of 1-3 devices.

Another advantage of FireWire should not be underestimated: Compared to Hi-Speed ​​USB, FireWire devices run Linux and Mac OS without any problems.

Laptops often use the smaller, four-pin i.LINK instead of the six-pin FireWire connector. How useful this connector is for mobile applications is debatable. Some users prefer to connect FireWire devices, while others avoid connecting to extend battery life. It should be noted that the i.LINK connector is devoid of two power wires.

FireWire is a good alternative for networking a small number of computers, as even older FireWire adapters' 400Mbps speeds exceed 100BaseT for simple networking tasks (see benchmarks).

Many users are not even aware of the possibility of organizing a small network through FireWire ports. If you link two computers, then one FireWire port for each of them will be enough. However, for networks with three or more PCs, the situation is different. You will need to use two ports for systems within the FireWire chain (one in, one out), while end computers only need one port.

Hi-Speed ​​USB can also be used for small networks, although this requires special cables.

The biggest problem with USB or FireWire networking comes with the operating system. FireWire networks work without any problems under Linux and Mac OS. However, under Windows, only IPv4 over 1394 is supported, as a result of which you can only use the IP protocol (however, it is the most common today). It is unlikely that a DHCP server will be able to run on a FireWire network, so you will have to assign all IP addresses manually.

Using FireWire entails certain security risks. Data transmitted between computers over a FireWire network can be intercepted at an intermediate host. At the same time, switch-based Ethernet prevents other computers from sniffing traffic between two machines (unless using a switch with port mirroring). If you don't care about security issues like this, then FireWire provides a solution that's good enough for your home network. In addition, such a network is faster than 100-Mbps Ethernet.

For our test, we used cards made by Century Global. The 1394b cards, known as the V1, are based on the TSB82AA2 chip from Texas Instruments, which Windows immediately recognizes as an OHCI-compliant 1394 device. Unfortunately, it is difficult to understand which mode the chip operates in. The manufacturer does not supply its own drivers or utilities.

Each adapter supports three 1394b ports that can operate in any configuration - with three terminals, or within a FireWire network with an additional terminal.

Century Global has wisely provided the card with a 64-bit PCI interface. With a transfer rate of 800 Mbps (or 100 Mbps), the 1394b standard almost reaches the bandwidth limit of the 32-bit PCI bus at 33 MHz (132 Mbps). In practice, however, the PCI bus is even slower because it serves all connected devices. Sound card, USB controller (mouse, keyboard, webcam, printer, scanner) and TV tuner - all of these devices consume PCI bandwidth. Therefore, the theoretical PCI bandwidth is available only in rare cases.

Three connectors allow the card to act as a "FireWire hub" on the network.

By using a 64-bit PCI interface, the 1934b controller is not limited by 32-bit PCI bandwidth.

One of the main uses of the 1394b standard is to connect high-speed external hard drives. The Fire800 can accommodate 3.5" UltraATA hard drives, and the device already supports the FireWire 800 standard.

Standard features include a regular FireWire interface (1394a) and a Hi-Speed ​​USB port that greatly increases connectivity.

Thanks to the small aluminum stand, you can mount the Fire800 in a vertical position.

For tests, we used a Western Digital WD2500JB hard drive at 7200 rpm with 8 MB of cache - one of the fastest hard drives on the market.

Compared to other hard drive enclosures, the Fire800 is very compact.

test system

This time we used two test systems because we wanted to compare the data rates of 1394b and 100 BaseT Ethernet. In addition to our test system to connect the hard drive (system 1), we also used a second computer with similar performance. Both computers were equipped with 3COM 3C905TX or 1394b V1 cards from Century Global.

System 1 (computer with external hard drive)
CPU	Intel Pentium 4, 2.0 GHz 256 KB L2 cache (Willamette)
Motherboard	Intel 845EBT Chipset Intel 845E BIOS BT84520A.86A.0024.P10
Memory	256MB DDR266/PC2100, CL2.0 Micron/Crucial
Controller	ICH4 UltraATA/100 Century Global 1394b V1
Graphic card	ATi Radeon SDRAM, 32 MB
HDD	IBM DTLA-307030 30 GB 7200 rpm, 2 MB cache 15 GB per platter
OS
Net	3COM 3C905TX, PCI, 100Mbps 3COM 3C9996B-T, PCI-X, Gbe
System 2 (for network test)
CPU	Intel Pentium 4, 2.2 GHz 512-KB L2 cache (Northwood)
Motherboard	AOpen AX4PE Max Chipset Intel 845PE BIOS 1.10 (May 29, 2003)
Memory	256MB DDR400/PC3200, CL 2.0 TwinMOS
Controller	ICH4 UltraATA/100 Integrated Hi-Speed ​​USB (ICH4) Century Global 1394b V1
Graphic card	ATi Radeon SDRAM, 32 MB
HDD	IBM/Hitachi IC35L060 AVVA07 60 GB, 7200 rpm, 8 MB cache 40 GB per platter
OS	Windows XP Pro 5.10.2600 SP1
Net	3COM 905TX PCI, 100Mbps 3COM 3C9996B-T, PCI-X, Gbe
Tests
Hard drive performance	c "t h2benchw 3.6
Data Transfer Diagram	ZD WinBench 99 2.0 Disk Inspection Test
Network performance	NetIQ Chariot 4.3
Drivers
Graphics driver	5.1.2001.0 (Windows XP Standard)
IDE Driver	Intel Chipset Installation Utility 5.1.1.1002
DirectX Version	9.0a
Screen resolution	1024x768 16bit 85Hz

Random access time, ms, less is better

Read performance, MB / s, more is better

Write performance, MB / s, more is better

Network bandwidth (minimum - average - maximum), Mbps, more is better

Response time (minimum - average - maximum), ms, less is better

Number of transactions per second (minimum - average - maximum), more is better

Real network bandwidth, transfer time 4.3 GB, less is better

Conclusion

FireWire 800, or IEEE 1394b, transfers data at up to 54 MB/s when paired with an external hard drive, easily outperforming other alternatives we've tested so far. When used as a network adapter, the 1394b standard provides transfer rates up to 400 Mbps. If you transfer data of several hundred megabytes, you will get a throughput of about 30 Mb / s, which far exceeds Ethernet by 100 Mb / s (see tests).

The FireWire standard is not ideal for network traffic. When used as a network interface, FireWire has a significant drawback - it requires compatibility with numerous applications, and not just the transfer of network traffic. Also, IPv4 over 1394 is hardly optimized for maximum performance. Also, the networking implementation under Windows does not have a good reputation, unlike Unix/Linux.

As we mentioned above, when building a network on FireWire, certain security problems arise. At the same time, connecting two computers via FireWire will provide faster speeds than 100 Mbps Ethernet. On the other hand, networks with three or more computers create additional traffic by slowing down the FireWire data rate. Therefore, it is difficult to say when an Ethernet solution becomes more effective.

Despite some shortcomings, we hope that the 1394b controllers will take their rightful place on motherboards, because the presence of a high-speed interface is often useful.

FireWire devices pair well with the PCI Express bus, as 250 MB/s per channel will be enough to connect a FireWire adapter without bottlenecking.

We should start by listing the rules to follow when capturing video from a digital video camera. But everything is much easier! There is only one rule - capture is performed only via the interface IEEE 1394(aka firewire, he is iLink). For the confusion in the names, we can thank the PR technologists of the companies who once tried to pull the blanket over themselves, “staking out” their own standard name for the company. To the great delight of beginners, this interface is increasingly called faceless in appearance. IEEE 1394, and less and less confusing "brand" names flash.

Perhaps someone will ask: what about the USB port? Why did the manufacturer add this interface to the camera? And it is intended only for copying digital photos from a memory card, a rare camera now does not have the ability to take digital pictures. If one of the readers has “an acquaintance recently leaked a video via USB”, there is only one advice: carefully ask if your friend is watching such a video on his mobile phone?

And yet, "in fairness and order for": USB and memory cards are used not only EXCLUSIVELY for photos. The fact is that some camera models still allow using branded utilities to capture DV-video via USB2.0, although it would be a stretch to call this method correct.

Any digital video camera has a jack that looks like a mini-USB port, but is smaller and often labeled with letters DV and side by side i. Those who have a not very old laptop do not have to think about it - most likely it already has a built-in IEEE 1394 port, and a cord is included with such a laptop. Just connect! But what about the owners of standard boxes from the store, called "home computer"? Rarely do any of them have such a port on the motherboard. And when buying a computer, of course, they did not think about the possibility of video processing. The solution is in the picture. Standard PCI board IEEE-1394 and a cord to it, the manufacturer does not name himself (probably out of modesty).

In appearance - the very inconspicuousness, and the cost of such goodness is now about $ 10-15. But this is all that is required for the "correct" transfer of digital video to a computer hard drive for further processing. If you, of course, have stocked up with the necessary program. However, further searches will convince you that the notorious capture can be done with the help of "combine programs", or even with the help of the built-in Windows XP, albeit primitive, but a video editor called Windows Movie Maker.

So, print this photo and go to the nearest computer parts store! Don't let the price confuse you, it's no secret that for just one bright sticker with the name of a well-known manufacturer, they sometimes ask three times against a noname product. As a rule, "loose" boards and cables from unknown manufacturers work just as well as those sold in colorful boxes. If you want to hear the opinions of other people first, read the corresponding in the forum.

And finally, the last tip (if you haven't already gone to the store). Take your camcorder with you. The fact is that manufacturers build different types of IEEE 1394 ports into cameras: 4 or 6-pin. Accordingly, there may be different boards, different cables on sale. Ask your dealer to find you a board and a cable that fits together and, of course, your camera.

It remains only to insert the board into the PCI slot of the computer (in Windows XP the drivers will be installed automatically) and connect the camera. Keep in mind: for your camera to be recognized by the system as a digital video device, it must be turned on and in Play mode, while those cameras that have a Video / Memory mode switch must be turned on in Video mode. During the driver installation process, the necessary files may be requested from the driver disk for your camera.

If you have connected everything properly, in Device Manager There will be two new items:

And in the tray next to the clock, an icon will appear indicating a digital video device ready for use:

Now your camera can work in conjunction with a computer as a DV camcorder, obeying the commands of the control program. Read about these programs in the relevant section. guidebook.

FireWire - the computer lexicon was enriched with just such a term due to the development of information technologies in the mid-90s. And for sure this name did not escape the attention of any user, not to mention computer specialists. What is the reason for the great popularity that this technology enjoyed, and what does it represent today?

The FireWire standard was born as a version of the IEEE 1394 high-speed serial bus standard for connecting peripherals to a personal computer. The author of this implementation was the notorious company Apple. The main advantage of FireWire was that it provided connection to up to 63 devices and data transfer at speeds up to 400 Mbps. Essentially, the IEEE 1394 standard is a description of a serial bus, as well as a means of providing a connection between one or more peripheral devices and a computer processor.

Devices equipped with FireWire, as well as other implementations of IEEE 1394, have the following features:

• A port with a simple connector located on the back of the computer and on various types of peripherals.
• Possibility to combine devices into chains in a simple way in various ways without the use of terminators.
• Using a thin serial cable that compares favorably with a thick parallel port cable.
• High data transfer rate, allowing you to deal with multimedia applications (200 Mbps and above).
• Ability to hot connect and disconnect devices.
• The ability to connect directly several devices without connecting them to a computer.
• Providing bus power.

Initially, various implementations of IEEE 1394 were supposed to be a replacement for all parallel and serial interfaces, such as COM () serial port and external SCSI.

How the interface works

There are two levels at which the FireWire interface operates, one of which is a bus inside the computer, and the other is designed to provide a connection between the computer and the device using a serial cable. The first versions of the standard provided data transfer rates of 12.5, 25, and 50 Mbps for the internal bus, while the cable interface supported speeds of 100, 200, and 400 Mbps. When operating, IEEE 1394 is capable of switching to any of the available speeds as needed.

The function of the internal serial bus is also to share memory space between devices connected to it. Each device can use 64-bit addresses, which provides flexibility in configuring devices in chains and organizing trees of devices connected to the same socket.

IEEE 1394 provides two types of data transfer - asynchronous and isochronous. The asynchronous way is more suitable for traditional applications that load data and then save it. With this method, data transfer is initialized, which can then be aborted after the required amount of data is in the buffer. The isochronous method maintains a constant pre-set baud rate. For multimedia applications, this method reduces the need for buffering and facilitates the output of continuous content.

Also, the IEEE 1394 standard contains a requirement for a maximum cable length that can connect two devices in a chain - 4.5 m. In the event that several devices are connected to the chain, the distance between the computer and the farthest element of such a chain can be much larger .

History and present of technology

Since the introduction of the interface, several versions of IEEE 1394 have been developed. In the most recent version, S3200, data transfer rates have reached 3.2 Gbps. However, this technology never became standard in the personal computer world, and there were several reasons for this.

At the time of its introduction, IEEE 1394 technology was considered much more promising than the similar USB technology, which in its early version could only support data transfer rates up to 12 Mbps. However, the higher cost of devices supporting FireWire played a role in the fact that the latter ended up being more common. The disadvantage of FireWire is also poor compatibility between different versions of the standard, which is expressed in particular in the fact that the port for older versions of the interface has a connector that differs from the port connector for new versions.

In addition, Apple's licensing policy, which limited the sale of devices equipped with it, prevented the widespread adoption of the technology. Currently, most modern PC motherboards no longer have a FireWire port in their composition, and this bus is used only in some specialized top-level systems.

Conclusion

Despite high performance and flexible configuration options, the IEEE 1394 port has not become a universal port for connecting high-speed devices. However, there are still quite a few motherboards that are equipped with connectors for connecting FireWire devices, as well as peripheral devices that support this technology.

the_tags("#"," #",""); ?>

We will devote this short article to the IEEE 1394 interface, which is found on almost all Apple computers under the name firewire. Firewire is only called firewire by Apple. Other companies call it iLink, mLan, and even Lynx. But the name is not so important as the essence is important. The dry definition sounds like this: this is a high-speed serial bus designed to exchange digital information between a computer and other electronic devices. In fact, this is a great way to transfer data, allowing you to quickly transfer files to / from your hard drive or camcorder, as well as take a fresh look at the capabilities of your Mac and free up a valuable USB port. So, we list all the advantages of firewire:

First, firewire, as mentioned, is very fast. Firewire 400 (IEEE 1394a), now found only in white Macbooks, loses USB 2.0 somewhat (in performance on operations with a large number of files), but IEEE 1394a outperforms USB up to 1.5 times in streaming operations. Well, firewire 800 (IEEE 1394b), as they say, tears the competitor to shreds (the transfer rate is increased to 3.2 Gb / s). And it is this connector that you can see on all current Apple computers, except Macbook and Macbook Air, while it is backward compatible with firewire 400. By the way, the 4-pin firewire 400 connector (deprived of power) is found on most modern PC laptops.

Secondly, firewire is often used as a means of copying movies from MiniDV camcorders to files. Copying from camera to camera is also possible. Historically, this method was the first way to use this tire.

Thirdly, connecting one poppy to another in Target mode. This function is useful if your poppy (pah-pah-pah) has played the box, and you risk doing the same without the information recorded on it. Connecting two Macs is easy, all you need is a 6-to-6-pin FireWire cable. First, turn off the computer that you will be connecting to the main one, then turn off all FireWire peripherals on both computers. After that, connect the FireWire cable, start the turned off computer and immediately press and hold the T key (in the English layout, of course). After that, a large FireWire logo will appear on the screen almost immediately, and, if you are using a laptop, a battery charge indicator (for PowerBook and iBook, you must first connect the laptop to the mains. By the way, you can close the laptop itself after entering Target Disk Mode). And in the Finder, meanwhile, the Macintosh HD (or other drive/drives) of the connected computer will appear. That's it, now you can use this disk with full access rights, that is, modify, copy, and delete information on it as you like.

And finally fourthly, the IEEE 1394c standard. Have you heard of this? But it is often mentioned when talking about wired Internet - this is RJ-45. The standard itself is rare and not widely used, however, due to its external resemblance, it was often confused with the 8p8c connector, a real ethernet connector. The confusion was not resolved, and the name of the rare standard became firmly attached to ethernet.

In conclusion, a remarkable fact. Whether angry at the growing popularity of the non-native format, or for some reason, however, since Vista, Microsoft has covered support for IEEE 1394-based network protocols in Windows, although 4-pin firewire connectors are found on most PC laptops. Unfortunately, Apple is gradually isolating the niche of using firewire. Previously, many of the company's players were connected to these connectors (and sometimes only to them!) for charging and synchronization, but in 2005, Cupertino refused the possibility of synchronizing the iPod, and starting from 2008, charging its internal battery. The only exception was the iPod Classic, but that's why it's a classic, so as not to completely abandon traditions.

So, firewire is primarily a high-speed data bus that allows you to conveniently and usefully connect an external hard drive or camcorder to your Mac, and sometimes take advantage of such exotic, but sometimes irreplaceable, features as Target Mode. The only thing that upsets is the cost of enclosures for external HDDs with firewire support - it is from 1.5 to 2 times higher than usual.

We highly recommend getting to know him. You will find many new friends there. It is also the fastest and most efficient way to contact project administrators. The Antivirus Updates section continues to work - always up-to-date free updates for Dr Web and NOD. Didn't have time to read something? The full content of the ticker can be found at this link.

FireWire Standards (IEEE 1394)

Semenov Yu.A. (SSC ITEP)

FireWire interface bus (IEEE1394)

Protocol firewire(also known as i.Link or IEEE 1394) is intended for personal computers as a high-speed serial interface, it can also be used for real-time tasks. The standard was approved in 1995. Standard IEEE 1394-1995 for a high-speed serial bus, specifies the serial communication protocol. The capabilities of the 1394 standard are sufficient to support a wide range of digital audio/video applications such as signal routing, home networking, audio/video device control, non-linear DV editing, and 32-channel (or more) digital audio mixing.

Features of IEEE-1394

• Transfer rates 100 - 200 - 400 - 800 Mbps
• Live connect/disconnect without data loss or service interruption.
• Free network topology, allowing both tree and loop (daisy-chains) schemes.
• Ability to set guaranteed bandwidth for real-time applications
• Standard connectors for various devices and applications.

4-pin connector	6-pin. connector	9-pin. connector	Purpose	Description	wire color in cable
	1	8	Nutrition	Unregulated DC; 30 V without load	white
	2	6	Earth	Return power ground and internal cable shield	black
1	3	1	TPB-		orange
2	4	2	TPB+	Twisted pair B, differential signals	blue
3	5	3	TPA-		red
4	6	4	TPA+	Twisted pair A, differential signals	green
		5	A screen
		7		-
		9	B screen
Braid			External	cable shield

Cable routing

FireWire allows connection of up to 63 peripherals. The standard allows communication between devices in P2P mode, for example, connecting a scanner and a printer without using memory resources or the computer's CPU. FireWire also supports the connection of multiple machines to the bus, and with the help of software it is possible to form IP networks between machines connected via FireWire. The protocol uses a 6-wire cable, which is more convenient than SCSI, and can also provide up to 45 watts of power per port. This makes it possible to dispense with separate network cables in the case of low-power devices.

FireWire 400 can transfer data between devices at 100, 200, or 400 Mbps (actually 98.304, 196.608, or 393.216 Mbps, and are called S100, S200, and S400). The cable length is limited to 4.5 meters, but in the case of a looped, daisy-like scheme with 16 cables, the total length of the connections can reach 72 meters. The FireWire 800 standard was introduced in 2003, and allows for up to 786.432 Mbps throughput while maintaining compatibility to operate at lower speeds.

IEEE-1394 architecture

The IEEE 1394-1995 standard defines two categories of bus: backplane and cable. The backplane bus is used to provide parallel data transfer, which is an alternative to serial data transfer between devices connected to the backplane. A cable bus is a tree-like network consisting of bus bridges and nodes (cable devices). 6-bit node name identifier allows up to 63 nodes connected to one bus bridge; The 10 bit bus ID allows for up to 1,023 bridges in a system. This means, for example, that up to 63 devices can be connected to one 1394 adapter card in a PC.

Each node typically has three slots, although the standard calls for 1 to 27 slots per PHY layer device. Up to 16 nodes can be connected to the network in a daisy-like arrangement using 4.5 m cables. This results in a total cable length of 72 m. The 1394 bus can be considered a plug-and-play bus.

The 1394 cable standard defines three basic transmission rates: 98.304, 196.608, and 393.216 Mbps. The user of the DV device uses the S100 speed, but most 1394 PC adapters support the S200 speed. The speed of the entire bus is usually the slowest; however, if the bus master (controller) uses Topology_Map and Speed_Map for a specified pair of nodes, the bus can support multiple (higher) baud rates for that pair of devices.

Isochronous and asynchronous data exchange is possible. The isochronous transmission mode of the 1394 bus provides guaranteed bandwidth and the necessary delay for high-speed transmission over multiple channels. When a bus is reset, or when a node is in isochronous mode, the node requests a bandwidth. If the desired bandwidth is not available, the requesting device periodically retries the requests.

IEEE 1394 is a platform independent standard. Its characteristics surpass known I/O interfaces. IEEE 1394 can provide a new parallel standard overlay interface for a port, IEEE 1284. Although IEEE 1284 4 - 32 Mbps rates are slower than 1394, 1284 finds its way into printers because it needs to be backwards compatible with the existing Centronics parallel interface. IEEE 1394 devices with different baud rates can communicate with each other, providing backward compatibility with lower speed devices.

Standard bus connections are made with a 6-wire cable containing two separate shielded twisted pairs for data transmission, two wires for power supply, and an overall shield. Twisted pairs are used to transmit and receive data. Power wires are used to supply voltage (8 - 40) V, at a current of up to 1.5 A. For galvanic isolation, transformers are used that can operate at a potential difference of up to 500 V, or capacitors that provide isolation at voltages up to 60 V relative to ground.

In 2004, the standard was approved IEEE 1394.1, which allows you to expand the number of connected devices up to 64449.

In 2005, a version of the standard was adopted IEEE 1394c, which allows you to use a Category 5e (Ethernet) cable. At the same time, it became possible to use IEEE 1394c and GigaEthernet in parallel on the same cable. The maximum declared segment length is 100 m. The maximum speed corresponds to the S800 - 800 Mbps.

External wired interfaces

02:39 29.04.2008
Alexey Sadovsky

FireWire Standard (IEEE 1394)

The standard, technically called IEEE 1394, was officially introduced in 1995. But its development began in the late 80s of the last century. It was started by the notorious Apple. Then she planned to release an alternative to the SCSI interface. Moreover, an alternative focused on working with audio and video devices. Over time, the development was transferred to the Institute IEEE.

IEEE 1394 has several names. FireWire is Apple's own commercial name. Today it is most often found paired with a technical name. Over time, the Japanese Sony, often going its own way, began to call this standard i.LINK. Panasonic did not remain in debt, offering its name: DV.

Despite the fact that FireWire was originally focused on audio / video equipment (it was even adopted as an A / V standard by an organization with an abbreviation HANA - High Definition Audio-Video Network Alliance, which is funny for our language), storage devices appeared with its support over time data such as external hard drives and optical drives.

Let's understand how IEEE 1394 works. Compared to USB, there are many differences. First of all, FireWire works on a peer-to-peer basis, not a master-slave one. It turns out that each device connected via FireWire has the same rank. One of the advantages of this approach is the ability to exchange data between devices directly without the participation of a computer, without spending its resources on it. Some readers may notice that USB On-The-Go provides the same functionality. But after all, it was originally in FireWire, and in the universal serial bus - just a couple of years after it appeared.

Just like USB, FireWire supports the Plug-and-Play system and hot swap (the ability to connect devices without turning off the computer). Unlike USB, FireWire devices are not assigned a unique identifier when connected to the system. Each of them has its own unique identifier that complies with the IEEE EUI-64 standard. The latter is an extension for MAC addresses widely used among network devices.

The topology of the FireWire bus is also a tree. If you need to increase the number of ports, you can connect special FireWire hubs. We did not find data on the depth of "nesting", so we assume that it can be quite large. But the maximum number of connected devices (assuming one FireWire controller) is 63.

And a little about the accepted standards and versions of the FireWire bus. In total, we counted five of them.

FireWire 400 (IEEE 1394-1995). The very first version of the standard, adopted in 1995. Supports data rates of 100 (S100 substandard), 200 (S200), and 400 (S400) Mbps. The cable length can be 4.5 meters. However, unlike USB, FireWire works like a repeater. Repeaters (essentially signal amplifiers) can be independent, increasing the total length of the cable, or built into hubs and devices with FireWire support. Thus the total wire length for the S400 standard can be up to 72 meters.

The basic type of FireWire connector is hexagonal and has six pins. In terms of its physical dimensions, it is somewhat thicker than the USB connector. But much more energy can pass through it. So the voltage can be from 24 to 30 V, and the current strength is 1.5 A.

IEEE 1394a-2000. This standard was adopted in 2000. He made some additions to the original FireWire specification. In particular, support for asynchronous data transfer, faster recognition of connected devices, packet aggregation, and an energy-saving "sleep" mode have been added. In addition, a small version of the connector was "legitimized".

A smaller version of the connector works with only four pins, but it can carry much less power. Today, this type is the most common and it is also most often found in laptops (only Apple continues to install six-pin connectors). You can connect a small connector and a large connector (or vice versa) through a special adapter cable.

FireWire 800 (IEEE 1394b-2002). In 2002, another addition to the FireWire standard was adopted. It was called IEEE 1394b (and the first version became known as IEEE 1394a) or FireWire 800. The number "800" directly indicates the maximum data transfer rate - 800 Mbps.

ConnectorFirewire 800

Twice the speed required a different type of connector. Now it already uses 9 contacts. At the same time, backward compatibility with FireWire 400 via an adapter cable was maintained. Of course, connecting old devices to a new port or vice versa will drop the speed.

Note that 800 Mbps is not the limit for IEEE 1394b. In test mode, transmission at speeds up to 3200 Mbps is supported, but this possibility will be disclosed a little later. It also became possible to use two types of cable: regular and optical. In the first case, the maximum length will be 5 meters, and in the second - up to 100 meters. The electrical characteristics of the updated standard have not changed.

FireWire 800 is most often found in workstations and Apple computers today. So far, if it is installed on conventional motherboards, it is FireWire 400. And so far, there are relatively few devices on the market that support the faster FireWire specification. As a rule, these are external hard drives combined into a RAID array. And even then, they most often support transmission over 3-4 interfaces (USB 2.0, FireWire 400/800, eSATA).

FireWire S800T (IEEE 1394c-2006). The main innovation of this standard is the support for the possibility of using a category 5e twisted pair cable, at the end of which ordinary RJ-45 connectors are routed. The first innovation also required the second - automatic detection of the connected cable. In addition, minor changes and corrections have been made to IEEE 1394b.

FireWire S3200. Well, about the future. The announcement of plans to release USB 3.0 could not but resonate with FireWire. Bottom line - in December it was announced intentions to submit a specification for a standard capable of transmitting at speeds up to 3.2 Gb / s. And in this case, it will probably be easier to do this than with USB. After all, the modern FireWire 800 can already transmit data at this speed. It remains only to debug the technology and test it well, and not seriously refine it.

The creators of FireWire are not going to stop there. The next in line is the standard with a transfer rate of up to 6.4 Gb / s. True, if the S3200 may appear within a year or two, then the second is still unknown when it will see the light of day. But it must be assumed that they will not delay with him.

At the end of the story about FireWire, let's try to figure out why, for all its charm, it is No. 2 after USB. The first argument against is the lower speed (if we compare the most common FireWire 400 and USB 2.0). However, we are talking about the theoretical maximum throughput. It is achievable, but only under certain conditions, which are rarely met in reality.

We didn't test the speed ourselves (after all, this is not a "Which to choose: USB or FireWire?" article), but we found quite a lot of reviews and notes on this topic on the Internet. So, in real situations, FireWire is almost always faster. The difference can sometimes be quite a lot - up to 30-70%. It is noted that USB 2.0 speeds rarely exceed 35 MB / s (with a theoretical peak of 60 MB / s), while FireWire quietly transfers data at speeds up to 49 MB / s.

And the power supply capabilities of IEEE 1394 are much better. When using a full-size six-pin connector, an external power supply is required much less frequently than with USB. And the devices would charge much faster.

So why does each computer have 4-10 USB ports and it's good if one is FireWire, and not vice versa? This is the same reason why 90% of PCs have Windows installed, and only 5% on Mac OS. At one time, Apple refused to start licensing its operating system to computer manufacturers, and as a result, Microsoft is now the first.

FireWire has not been so categorically restricted (such that it can be installed on "apple" systems), but Apple, as the owner of the patent for the technology, quite legitimately wants to receive royalties. For computer manufacturers, the fee is $0.25, and for equipment manufacturers (cameras, external HDDs, etc.) - $1-2.

USB is originally an open standard targeted at a wide audio audience. That is, it is trivially cheaper, which is why everyone preferred it, even Apple itself does not disdain it at all (suffice it to recall the MacBook Air, equipped with only one USB and deprived of traditional FireWire, as well as transferring the iPod from FireWire to USB).

We recommend using FireWire whenever possible, especially if you need to transfer large amounts of data. For example, when connecting an external hard drive. However, the latter type of device already has its own standard - eSATA.