Under the Desktop: Stoking the FireWire Flame

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There’s a moment in “The Wizard of OZ,” when the mayor of the Munchkin city declares: “This is a day of independence. Let the joyous news be spread, the wicked old witch … blah, blah blah.” Then the crowd erupts in a Technicolor mosh. For content creators, an event of similar import occurred as earlier this month when a ZDNet News story reported that Microsoft’s forthcoming Windows XP operating system will support FireWire instead of USB 2.0 (USB users, don’t fret: USB 1.1 will still be supported). But in this instance, the hero is Microsoft, and the revolution went unheralded, though it was certainly celebrated in private by some FireWire fanatics.

FireWire, or IEEE 1394, is familiar to content creators as an easy-to-use connector for an increasing list of peripherals — foremost, digital video cameras — and over the past couple of years as a replacement for SCSI in desktop storage. (Nitpicking readers, delay the flames. Yes, this writer knows that today’s FireWire is actually 1394a, and the first FireWire standard was called 1394-1995. Go figure.)

Universal Serial Bus 2.0 is promoted by the USB Implementers Forum, spearheaded by Intel and a group of manufacturers including Compaq and Hewlett-Packard. The next-generation standard is much faster than the current 12 Mbits/sec standard, supporting speeds up to 480 Mbits/sec. FireWire, on the other hand, tops out at 400 Mbits/sec.

So what’s the big deal? Sure, it’s interesting that Microsoft broke ranks with its buddies. But why is the backing of Microsoft so important to 1394 users? After all, isn’t there a thriving FireWire market? Apple and Sony now offer it on both desktop and portable systems (although Sony dubbed it iLink). Owners of machines without the interface can pick from a growing number of 1394 host adapters. And customers can chose between large and small FireWire hard disks, CD-ReWritable drives, a wide range of digital video devices, and now scanners. So, what me worry?

The Great and Powerful FireWire?
Despite the plethora of devices, the FireWire market is not as robust as it seems, especially to us with a content-centric perspective. A peripheral vendor might view the market differently. After all, the list of vendors offering machines with 1394 integrated on the motherboard is slim, and one of those is Apple; though a significant platform for content creators, Apple holds but five percent or so of the total PC market. Unless they have a major stake in the content-creation market, most peripheral vendors pay attention to the mainstream numbers and invest dollars and resources accordingly.

A case in point is the storage industry’s wishy-washy support for FireWire hard drives. Currently, there are no native 1394 storage devices, despite the assertions of industry pundits, who really should know better. Native interfaces talk directly to the drive. All so-called FireWire drives combine an ATA/IDE mechanism with a “bridge” chip that provides support for 1394.

This IDE-to-FireWire bridge scheme can create a performance bottleneck, as was the case with the first round of chips, which topped out at about 15MB/sec. The interface using these chips is much faster and easier to use than the Fast SCSI-2 port on older Macs, but the transfer rate is slower than the 25MB/sec to 35MB/sec possible from a single, high-performance IDE drive. Several vendors recently announced FireWire drive enclosures that use a faster IDE-to-1394 bridge chip from Oxford Semiconductor that permits speeds between 30MB/sec and 40MB/sec. Some of the vendors offering products with this chip include ADS Technologies, Granite Digital, LaCie, and Other World Computing.

Around the storage industry, an interface is recognized as coming of age when manufacturers offer drives with a native interface. Today, that includes IDE (officially, ATA), flavors of Ultra SCSI, and Fibre Channel, although drives with the latter two interfaces come with premium price tags.

Throughout the previous decade, FireWire was rejected as a native interface. I remember an Apple demonstration of a native FireWire drive five or six years ago at Comdex in Las Vegas; it used a Quantum mechanism (Quantum this month announced it would give up manufacturing hard drives and concentrate on storage solutions, i.e. big server storage). Although there were frequent rumors that this or that manufacturer would build such a drive, none made it into production.

Given the vicissitudes of the storage market, Microsoft’s support for 1394 is a huge win for content creators. It will keep momentum behind the standard and perhaps spur additional system vendors to offer the interface as standard equipment. And its backing will guarantee a continuing wide variety of peripherals for storage and networking. Plus, it will enable FireWire devices to be competitively priced with devices based on other standards.

The Road to the Emerald City
With USB 2.0 looming over the storage and peripherals market, news of solid Microsoft support for 1394 also adds weight behind future faster — much faster — versions of FireWire. According to industry mavens, FireWire offers additional performance benefits over USB 2.0, beyond the speed of data transfer over a cable.

For a deeper understanding of the differences, I spoke with Michael Teener, the former godfather of FireWire at Apple and now Chief Technical Officer at Zayante Inc. of Scotts Valley, Calif., a developer of 1394 programming tools.

FireWire holds a significant architectural advantage over USB, Teener said. In a nutshell, USB 1.1 and 2.0 require the main system processor to do a lot of work, constantly checking in with devices and data. FireWire controllers are more complex and independently handle many of these tasks.

According to Teener, this difference weighed heavily in Microsoft’s decision to back FireWire. The company discovered that USB’s reliance on the main CPU takes an even greater toll on performance with the latest generation of processors, including the Pentium 4 and the higher-speeds of the PowerPC G4. These processors achieve higher frequencies with longer data pipelines but also have longer latencies. The added interruptions from USB peripherals can create lots of the longer latency delays, degrading overall system performance. “Interrupts are death to modern processors,” Teener said.

He added that Microsoft’s low-level support for USB 2.0 in Windows XP was no simple job and the work wasn’t ready for prime time. From a high level USB 2.0 looks like its predecessor, Teener said, but “under the hood, it’s really different.”

Microsoft will avoid this extra burden when it adds support for the forthcoming next-generation FireWire interface, Teener said. Dubbed 1394b, the updated interface will support speeds between 800 Mbits/sec to 3.2 Gbits/sec. Teener expected several 1394b products to be released by the end of the year, including a host adapter card. And 1394b is backwardly compatible with current versions.

As a measure of its commitment to FireWire, Microsoft in late July will host this year’s 1394 Trade Association Developers’ Conference. Held at Microsoft’s Redmond headquarters, the event will feature demonstrations of 1394b products, networking, and new wireless support.

We’re off to See the Wizard
There’s an ironic twist in Microsoft now siding with FireWire, given its shaky history with the standard.

In the mid-’90s, Microsoft and Intel proposed an external storage initiative called Device Bay, which provided a 1394-based backplane architecture and removable modules for a variety of storage formats. There were similar modular storage systems with a SCSI interface, primarily sold into the Mac market, but they had SCSI’s termination and cabling hassles. Although aimed at providing easy-to-use storage and expansion for consumer Windows systems, Device Bay was to work on any platform, including the Mac.

Microsoft eventually balked at supporting the scheme and the proposal fell through. Confusion over Apple’s efforts to twist some extra licensing bucks at that time may have also had something to do with it. Everyone pointed fingers at each other. Still, like a cat with a few lives remaining, Device Bay survives as a plan that combines 1394 and USB.

As expected, the die-hard Microsoft bashers are somehow furious with the arrival of Windows into the 1394 circle. We wuz there first, they say. To them I repeat the wisdom of the Talmud: “Weep for the person who does not recognize their own fortune.” This month’s FireWire tidings are good news for us all.