[johnzoidberg]

I have an external FW 400 hard drive plugged into my 12" PowerBook, and an iSight plugged into the hard drive. I read on Apple discussion boards that it is not safe to have both the iSight and hard drive plugged in at the same time, because the iSight, somehow, can lead to corrupted data on the external hard drive. Does anyone have a similar set-up? Is it safe to use both devices at the same time?

[d.fine]

I used the exact same setup not so long ago, didn't have any problems, and I did huge backups to that HDD every day ... all my data is still there as it should be.

[bmhome1]

Search the subject at MacInTouch.com, there's a lot of scary stories about iSights and firewire drives both powered at the same time, bus-powered firewire drives in particular. The safest strategy is to use a powered hub to connect both to so the firewire port doesn't have to power either.

[Cadaver]

I tried this... lead to data corruption on the FireWire drive. Fortunately, DiskWarrior was able to work its magic, and I didn't loose any data.

I also suggest an externally powered FireWire hub if you want both devices plugged in through the single FW port on the computer.

[johnzoidberg]

So the cause of data corruption is not the FW bus itself, but using the bus power to drive both devices? My external FW hard drive is connected to a power adapter, so should that prevent any potential problems?

[bmhome1]

No one really knows for certain, but the high-power draw of the iSight has been implicated along with Apple's choice of absurdly thin firewire cabling. Best bet is to buy the fatest, most over-designed connector cabling for firewire you can find.

Also, just plug in iSight only when actually using it and shutting down connected firewire drives during its use if you want 100% assurance. And the super-cautious now avoid hot-power plugging firewire devices when practical. The more one reads on the whole subject, the less confidence in the promise of firewire powered-up device hotswapping.

Also, it has become more apparent how too easy it is to unwittingly force-plug in firewire cables upside-down, spreading open seamed one-way socket designs (better, more robust design sockets are seam-free and won't splay open) and the resultant catastrophe of instantly destroying the port and/or logic board.

[Cadaver]

Originally posted by johnzoidberg:
So the cause of data corruption is not the FW bus itself, but using the bus power to drive both devices? My external FW hard drive is connected to a power adapter, so should that prevent any potential problems?

My hard drive was (is) also plugged in to the wall AC, not bus powered.
What seemed to happen was too much current draw off the second (daisy-chain) FW port on the hard drive. Apparently, some FW cases and their power supply don't actually provide any extra bus power to the port; the power supply was (is) simply designed to power the HD itself.

A powered FW hub will, if its a well-designed hub, inject more current in to the FW bus to drive more devices.

[TailsToo]

I have not had any problems with my iSight plugged into the back of my AC powered Western Digital Hard drive.