firewire device hierarchy: does it really matter?

FireWire; it just sounds fast, doesn’t it? At the very least, it certainly sounds faster than USB. Perhaps that was Apple’s intention when they sat down with Sony, Texas Instruments, and many others to create an amazingly accessible data transfer specification that conjured up the image of reliability ease of use within the minds of users. However, if FireWire has one flaw, it’s that it’s too easy to use. What do I mean? Let’s compare the connectors for USB and FireWire. While USB has an A and a B side, FireWire simply has a side. Sure, FireWire has 2 different specifications with 2 distinctly different connectors, however, each has only one connector style.

Back to the point…
If FireWire has one flaw, it’s that it’s too easy to use, because there’s often a great deal of confusion as to in what hierarchical order devices get connected, as any device can seemingly be plugged into another. In reading audio forums and message boards over the past 2 weeks, I have found nearly two-dozen post asking which comes first, the audio interface or the drive. Why? More often than not, engineers are concerned about possible audio drop outs and decreased drive performance, which aren’t completely unreasonable concerns.

Why is this an issue?
Can’t devices be plugged in however I want? Well, that depends, really. Some device manufacturers like MOTU and Apogee make no mention of a device hierarchy preference. Others, such as RME, have seen notes in their forum that when using on Mac’s containing the LSI/Agere FireWire chip-set their audio devices only work when a FireWire drive is placed between the audio interface and the computer. Others still, such as industry leader Digidesign, note the following. Personally, the fact that this is spelled out so plainly just makes me feel it’s a necessity.

From the 003 Getting Started Manual
Connect FireWire hard drives directly to a FireWire port on your computer.

The FireWire ports on 003 and 003 Rack do not pass audio data when they are powered off. If you daisy-chain FireWire devices from your computer, it is best to connect FireWire hard drives directly to your computer and not to 003 or 003 Rack. This will prevent hard drive errors and data loss in case 003 or 003 Rack is powered off.

If your computer has only one FireWire port, connect the FireWire hard drive directly to your computer and then connect 003 or 003 Rack to an available FireWire port on the drive.

via Digidesign (pdf)

via Apple, Wikimedia Commons, and OWC


Ok, so this is just for ProTools users and the paranoid?
No, not really… Personally, I think it’s good to adopt a set methodology of doing something even as mundane as hooking up a hard drive and stick to it, which is why I practice this habit. Also, for the other end of paranoid who are worried about audio drop outs, sticking to a stable setup will allow you to trouble shoot the root cause of those issue as it’s probably not FireWire bandwidth.

Well, a number of reasons. If you read the basics of the IEEE 1394 spec (it’s a dry read) or consult the 1394 Trade Association you’ll find that FireWire can connect up to 62 peripherals. Now, obviously you’re not going to do something foolish like that in a recording session. In fact, if you read the Digidesign ProTools 8.0 LE System Requirements, you’ll see that Digidesign recommends no more than 4 daisy chained FireWire drives, which are not to be mixed of FireWire 400 and 800. However, even at 4 drives, that gives you quite a bit of leeway before you should start to have any problems.

So, I should just trust you?
Well, ultimately that’s you’re decision, isn’t it? Personally I think this is sound policy and given what I’ve found I’m not the only one. However, if you’re a Mac or PC user with multiple free FireWire ports or a DAW user that uses a USB Hard Drive (shame on you!), then this really is of little concern to you. Either way, if you’re ever in a situation where the hierarchy of FireWire devices is at issue, I’d recommend placing hard drives in line before audio interfaces.

What’s your take on FireWire connectivity? Do you have a set device hookup methodology? Try it a different way each time? Whatever your thoughts or experiences, let us know in the comments below!

thumbnail via Apple

Kyle P. Snyder

Kyle P. Snyder is an engineer, educator, and consultant skilled in audio recording and mixing, sound design for film and video, facility design and integration, and live event production. Snyder works remotely on projects of all sizes from his Ohio-based studio, White Coat Audio, LLC. He is also a faculty member within Ohio University’s School of Media Arts & Studies dedicated to the advancement of audio education for engineers at every stage of development where he routinely teaches courses in music production, critical listening, and sound design for film and video.