More on the Dangers of Hot Swapping FireWire Devices

Back in February, I wrote here about how I (foolishly in hindsight) plugged the FireWire cable for my CD burner into the PCI FireWire adapter in my Umax SuperMac S900 while it was booting up. This caused a hard crash, and the S900 subsequently refused to boot properly with the OS 9 FireWire extensions enabled.

I was eventually able to get the PCI FireWire card working again by removing it from its slot, rebooting the computer, shutting down, and reinserting the card. However, I am a lot less sanguine about hot-plugging FireWire devices than I used to be.

Last week I received the following note from reader John Davis:

Re: FireWire: Hot Swapping Isn't Always a Good Idea

Hi Charles,

I just read the above article, and I too agree it's ironic that the highly touted "hot swap" advantage of FireWire technology is actually a disadvantage when considering the cost of replacing or repairing damaged equipment. In my case the situation has proved extremely costly.

I manage the Center for Digital Media at the San Francisco Art Institute, where we run a couple Mac networks with approximately 40 FireWire enabled computers and roughly 7 or so FireWire peripherals. These peripherals include video decks, CD burners, and peripheral hard drives. Of these, three Panasonic video decks now have burnt out motherboards from hot-swapping to and from Apple G4 towers (the decks cost $900 new, and $1,200 to replace the motherboards). Our JVC video deck has been in for repairs to the FireWire bridge three times at approximately $400 per repair. Two FireWire peripheral hard drives have fried, and four peripheral FireWire CD burners have burnt-out bridges, making the cases useless (we have since loaded those CD burners as internal units in the towers). This puts the grand total of damaged and repaired FireWire devices at roughly $3,500. Quite a nut for the convenience of hot-swapping, wouldn't you say?

The most frustrating part about this is that Apple won't recognize the problem. They blame the devices and the "questionable" quality of the manufacturers' construction. They claim that the Apple equipment is tested and reliable and that all such problems lie with the manufacturers. I say that's B.S., and that at least, Apple should recognize this as a major issue and warn consumers in advance that this problem exists.

What do you think?

Sincerely,
John Davis

Well, John, it appears that the problem is even worse than I imagined when I wrote the article.

I agree that Apple should provide more information and warning about potential FireWire problems. My iBook owner's "manual" (i.e.: thin pamphlet) says essentially nothing about FireWire, other than identifying the location of the port.

Certainly most FireWire peripheral vendors trumpet hot plug ability as a major feature of FireWire.

By coincidence, WiebeTech has just published a white paper that provides useful information on the causes and prevention of FireWire port failures, especially in host computers.

"We have seen much interest on the part of FireWire users regarding this subject as judged by recent comments on industry websites. We think users will be interested in reading our analysis of the cause and prevention of port failures," said James Wiebe, CEO of WiebeTech.

Statistics for total failures of FireWire ports is not known. Judging from the number of posts on Apple's website:

<http://discussions.info.apple.com/WebX?14@103.67TDaKsJjbJ.2@.ef0a4bc>

as well as posts on the website:

<http://www.macintouch.com/firewirereader02.html>

this topic is assumed to be of interest to many readers.

The purpose of this report is to provide background and technical analysis of the failure of the ports. In conclusion, methodologies will be suggested which may substantially reduce the incidence of damage to host ports.

The article lists a number of possible causes of failure and potential workarounds and preventatives, as well as outlining measures WiebeTech has taken with its own products to help minimize the potential for damage, such as power switches on bus-powered FireWire devices and a technique that allows the power supply of the FireWire device to "soft start" while the device is still in the off position. The white paper is well worth checking out for anyone interested in or concerned about this issue.

Your hardware failures all seem to have been in third-party devices, rather than the ports or motherboards of the Macs themselves, but there have been lots of reports of FireWire port failures as well, particularly with Titanium PowerBooks. One possible preventative workaround for folks who do a lot of hot-plugging would be to use PCI or PC Card FireWire adapters, even on machines that have built-in FireWire support, as a "sacrificial" buffer, if you will, that will be cheaper to replace than a motherboard if a failure is experienced.

I'm wondering if using a FireWire hub rather than a direct cable connection might protect peripheral devices to some degree.

It is considered heresy to say so by some in the Mac community, but I have to wonder whether USB 2.0 might actually be better technology. I'm not saying that it is; I don't know enough about the engineering distinctions between FireWire and USB 2.0 to make an evaluation. However, as nice as it is when it works, FireWire obviously has some issues.

However, one clear advantage that USB 2.0 does have is that with so many more companies supporting its technology, a much wider selection of peripherals - such as digital audio and video devices, DVD-R and CD-RW drives, digital cameras, and whatever - are going to be available with USB 2.0 than with FireWire.

Anyway, check out that WiebeTech article and be careful plugging in those FireWire devices.