Where's the Fire?

It was supposed to be one of those Holy Grail technologies, the perfect way–both fast and convenient–to connect external devices to your personal computer. On the PC side, it's known as IEEE-1394; Sony calls it i.Link. But Apple named its cool technology FireWire.

Even though FireWire was officially standardized back in 1995, it has been more a myth than a reality. However, Apple changed all that when the company added two FireWire ports to the back of every blue-and-white Power Macintosh G3.

Hope blossomed among the many Mac owners who've been eagerly awaiting a SCSI replacement. FireWire was the technology that would put an end to the days of SCSI-termination hassles and ID conflicts that lead to Macs that lock up or do nothing but show a blinking question mark.

But FireWire was never positioned as a mere improvement on SCSI: it's also a technology that lets you connect many more devices per chain (63 to be exact; 9 times as many as SCSI) and supplies its own power (so that many devices don't need any external power supply).

And then there's speed: FireWire provides a tenfold increase in bandwidth compared to the built-in Narrow SCSI ports previously found on Power Macs.

Yet six months after the arrival of the blue-and-white Power Mac G3s, the FireWire universe is still a bit tepid. FireWire devices–such as CD burners, scanners, and hard drives–are only just beginning to appear.

Like any other technology, FireWire needs time to become prolific, but is this promising new connection gaining momentum or just muddling along?


FireWire is Apple's answer to some of the most annoying and common problems with connecting external devices and getting them to work. Imagine a peripheral-connection scheme that lets you blithely connect a mix of hard drives, CD-R drives, scanners, and digital cameras without worrying about which order they're in–or whether they'll play nicely together at all–on the chain.

To anyone who's used external SCSI devices, especially scanners and other miscreants, FireWire is nothing short of a miracle. No longer will anyone have to move devices up and down the chain, with some devices demanding to be at the end and others at the front. With FireWire, it's plug-and-play in the truest sense–plug devices in and they work, at least theoretically.

Hot-swappability is another key FireWire feature: you can connect FireWire devices to and disconnect them from your Mac without shutting down. ID conflicts are a thing of the past, since FireWire devices talk among themselves and sort out which one gets which ID.

A Big Boost

Traditional Narrow SCSI, Apple's original external connection of choice, was first used on the Mac Plus, in 1986. This state-of-the-art (for the 1980s) technology had a throughput of only a measly 5 megabytes per second (MBps). Although there are faster, more expensive versions of SCSI, Narrow SCSI has been the built-in standard against which all comers are measured. Apple's FireWire allows throughput of up to 400 megabits per second (Mbps), which translates to 50 MBps–a substantial boost. And an 800-Mbps version of FireWire–four times faster than today's–is already nearing completion.

Just because FireWire has this tremendous bandwidth available doesn't mean that all FireWire devices will automatically offer such high performance. As with other technologies, the maximum throughput of FireWire doesn't always translate into real-world results.

Today's standard hard drives typically move data back and forth between the computer and the drive at 10 to 15 MBps. So despite the availability of up to 50-MBps throughput today, the hard-drive mechanisms–and not FireWire itself–determine the speed of FireWire-connectable hard drives.

Four-Alarm Fire

Not only is FireWire fast and easy to use but it also supplies power–up to 60 watts–over its cable. This means that many FireWire devices with smaller power requirements don't need an external power source.

VST's small FireWire drives, for example, contain hard drive mechanisms that were designed for laptops and hence have a small appetite for electricity. When you plug the FireWire cable into the drive, you not only establish the data connection to the computer but you also power the drive.

Sixty watts is enough power to run one–or two, at most–of these small drives. Sony's take on FireWire, i.Link, omits the power supply from its cables. For this reason, you need a cable adapter to connect i.Link devices to a Mac.


To help determine the current state of FireWire, Macworld Lab tested a 4GB FireWire hard drive from VST Technologies (978/263-9700, http://www.vsttech.com ) and found that FireWire's software is definitely still teething.

Not only is Apple's own FireWire system software changing rapidly but the drivers–which form the conduit between the system software and the FireWire hardware device–are also going through a similar evolutionary process. In addition, many FireWire hardware devices contain their own built-in software, known as firmware, that can affect the devices' behavior and performance.

We compared three software combinations, involving two versions of the Apple FireWire driver software and two versions of the VST driver and firmware, on the same VST hard drive (see the benchmark, "Fire Drills"). With the latest Apple software and the most recent VST driver and firmware, the hard drive performed much better than with the software combination that came with the VST drive when it originally became available. Even such simple software upgrades can provide a significant performance increase.

The Real World

Keep in mind that even with FireWire's flexibility, you must be careful when adding or removing devices. For instance, if you add a hard drive to a chain while you are burning a CD in a FireWire CD burner, you are likely to end up creating a coaster instead of a usable disc. That's because anytime a device is added to or removed from a FireWire chain, all the other devices pause to make sure that their connection is still available. This rechecking of all the connected FireWire devices unavoidably interrupts the CD-creation process.

Today's FireWire on the Mac has other shortcomings that need to be addressed by Apple. For example, you can't currently boot a Macintosh from a FireWire drive, although Apple has promised to offer this ability before the end of the year. In addition, the way Apple's FireWire system software works currently prevents the Finder from displaying the icons of files whose applications are stored on FireWire drives. Finally, when reading from and writing to FireWire drives under the Mac OS, even the fastest Macs can suffer from unresponsiveness, especially during long file copies. This is in stark contrast to Apple's SCSI system software, which provides smooth background file transfers.


If FireWire is so wonderful, why isn't it ubiquitous yet? Here's the problem: until there are more computers with FireWire ports, building FireWire devices is prohibitively expensive. Luckily, the paucity of ports will soon be alleviated, with the inclusion of FireWire across the Macintosh product line, not just in the "professional" desktops.

Because FireWire is only just arriving on PC motherboards, there are no "native" FireWire storage devices today. All storage devices that use FireWire employ a "bridge chip," so called because it translates between FireWire and ATA, the mass-storage connection standard used in today's Macs and Windows PCs. But if Windows-based computers offer FireWire, less expensive, native FireWire devices should appear.

Another reason for the slow acceptance of FireWire is the growing popularity of the Universal Serial Bus (USB): many low-bandwidth devices don't need more than the 12 Mbps of bandwidth that USB offers (see the diagram, "FireWire Speeds Ahead"). USB's success means that FireWire will initially become popular only for high-bandwidth applications that simply must have more speed than USB delivers. But don't frown just yet. Once it costs less to build FireWire devices, we can expect the number of peripherals to grow rapidly.

Although FireWire hasn't been adopted as quickly as Apple would hope, there are interesting technology developments in each of the following categories.

See the table "FireWire Products"
Digital Video

The Digital Video (DV) standard uses FireWire for connectivity. Typical DV cameras, such as the Canon Elura, can be remote-controlled from a Mac via FireWire, with software such as Apple's Final Cut Pro (see Reviews, August 1999). Such software transfers DV data to disk for later editing.

FireWire has an additional media-specific feature–isochronous transfer–that guarantees that a particular stream of data traveling across the FireWire cable will always have enough bandwidth. This is critical for video and audio applications, because if the available bandwidth drops below a certain threshold, disruptive dropouts happen.

Storage

Hard drives, CD-ROM drives, CD-Recordables–storage is a hot place for FireWire. The Device Bay standard, under development for the Windows OS, is driving many hardware manufacturers–such as VST Technologies, Mactell, Sony, and Indigita–to offer FireWire compatibility. The Mac will benefit as a result.

However, until native drives become available, FireWire-to-ATA bridge chips will be used for mass storage, including hard drives, DAT drives, and CD/DVD readers and burners. These bridge controllers are still being refined, and performance is improving as new versions of the bridges' firmware are released.

PC/PCI Cards

If you think FireWire is only for owners of blue-and-white G3s, think again. Newer Technology, Racom, and VST Technologies have announced FireWire cards for PowerBooks. These CardBus cards provide greater bandwidth between the card and the computer. Since the PowerBook 3400, Apple's portables have included built-in CardBus support.

Owners of older Macs can also add FireWire to their computers, by purchasing a PCI card from a manufacturer such as Orange Micro or Adaptec. One shortcoming of this approach is that some manufacturers, notably VST Technologies, won't support devices running on a Mac unless the Mac came with FireWire already built in. Currently there seems to be no way to retrofit FireWire into iMacs, but we expect the next generation of iMacs to have FireWire built in.

Scanners

Although there are plenty of inexpensive USB scanners, the USB connection is too slow for frequent high-quality scans. For the best results, you need FireWire, and until now, finding a FireWire scanner was nearly impossible. Thankfully, Umax has announced the first scanner for FireWire, the PowerLook F3.


FireWire also promises to become a hot ticket in consumer electronics, where it's intended to replace the rat's nest of cables behind today's televisions and stereos. FireWire speakers, DVD players, and amplifiers are coming to a superstore near you over the next year or two. Instead of having your receiver be a home-audio/video cabling hub, you'll be able to simply add FireWire-enabled devices such as TVs or set-top boxes to the chain–a huge convenience, since each device will have at most two FireWire connections, one going in and the other going out to the next device on the chain.

Another clear indicator of this hopeful future is Sony Electronics' forthcoming PlayStation 2, which will have at least one i.Link port built in.


After a long dormancy period and many missed opportunities by Apple, FireWire is gaining momentum of its own accord. The current standard is constantly evolving, with 800- and 1,600-Mbps versions already well under way. And if the Device Bay standard is adopted widely, FireWire will proliferate through the Wintel world with great speed, making more FireWire peripherals available at lower prices.

However, what will ultimately happen with FireWire remains a big question. Will this technology on the back of your Mac make the computer easier to use and bring computers and consumer electronics closer together?

Given the recent interest in FireWire from so many directions, we believe that the question for Mac users is not whether FireWire will succeed but whether Apple will be able to keep up with the remarkable technology it created.

Also see the sidebar "FireWire at Work"

November 1999 page: 108

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