How dangerous is it to hot-plug FireWire 400 devices?

Question

Level 2

222 points

How dangerous is it to hot-plug FireWire 400 devices?

I've had my MacBook since 2006 and, on the odd occasion, I've used the FireWire 400 port for connecting an HDD caddy or for networking between two Macs. I've always hot-plugged devices without a worry. I've always assumed that's what FireWire was designed to do.

However, recently I purchased an M-Audio ProFire 610 - it's a multi-channel digital audio interface - and plastered all over its documentation (and the website) are warnings that you MUST turn the device off before plugging or unplugging. I was quite surprised by this, and wondered if it had anything to do with the device being dodgy.

http://forums.m-audio.com/showthread.php?17235

Apparently then, this is not an issue with M-Audio devices, but with ALL FW400 devices... Although it's the first I've ever heard about it, which I find a bit odd... If there really is such a fundamental flaw in FW400, why wouldn't I have heard people complaining on Mac forums about fried FireWire controller chips?

Is it dangerous in general, or do you think that perhaps M-Audio are trying to cover-up for shoddy manufacturing? Like I said I've never had any problems hot-plugging FW devices before and now I'm really paranoid, turning the computer off every time, which is really frustrating.

Not only that, but supposedly the issue is power arcing onto the data pin... But if you power down any Mac device (MacBooks included), they still deliver power to the FW device. So how safe does powering it down really make it anyway?

MacBook, Mac OS X (10.6.8), 1,1 Core Duo 2.0 GHz 2 GB RAM

Posted on Feb 2, 2012 12:04 PM

Reply

Answer 1

Best reply

John Galt

Level 10

141,060 points

Feb 2, 2012 12:20 PM in response to Jowie

The controversy surrounds potential for component damage if the connector is not inserted properly.

I surmise it's an overabundance of caution, understandable given the inability for any manufacturer to guarantee every device and FireWire cable connected to it will always be fully compliant with the IEEE specification.

To my knowledge no widespread failures of FireWire components on Macs has been reported.

Reply

Answer 2

Jowie Author

Level 2

222 points

Feb 2, 2012 2:20 PM in response to John Galt

Thanks John,

That makes me feel a bit safer... I'm not sure how worried I should be about hot-plugging FW devices in future though. Should I be specifically careful when hot-plugging the M-Audio device, or are they all pretty much the same? May I ask do you personally hot-plug your devices?

I heard that the problem is specific to FW400 and so I guess eventually (within the next year or so) I might be getting an MBPro and so it shouldn't be a problem due to its FW800 port.

Have most of the failures of FireWire components been on PCs then? I was worried it would be more likely Macs with the issue, since a lot of PC FireWire ports are 4-pin (no power)...

Reply

Answer 3

John Galt

Level 10

141,060 points

Feb 2, 2012 3:18 PM in response to Jowie

I can only speculate that there is nothing inherently different about the M-Audio device and they are just being overly cautious. Granted, powering down is the safest thing to do but I think it's unrealistic to expect users are going to tolerate that all the time.

I have been using FW400 ever since the first iMac came out with it, over ten years ago, and I just removed that computer from active service last summer. I never gave hot-plugging a second thought. I still do it routinely with cameras and an older iPod with my newer iMacs. Never had a problem.

PCs are a different story since shoddy design is simply a characteristic of the low-end market. Manufacturers skimp on little things that literally amount to saving save a buck or two. So I wouldn't be surprised if failures are more prevalent among PCs.

Having been on this forum for twelve years, and its predecessor before that, I became familiar with many common afflictions among Mac users. FireWire is not among them.

Reply

Answer 4

Jowie Author

Level 2

222 points

Feb 3, 2012 5:49 AM in response to John Galt

Marked as "correct answer" if only because that's what I wanted to hear 🙂 but I'm going to follow this up on M-Audio's forum to see what they have to say about the situation. Thanks!

Reply