[serr]

Here's a weird one...
I'm trying to help a buddy with a 3rd gen MBP and a new WD 'My Studio' firewire external drive.

He can mount and use the drive but is unable to boot from it. When starting up his machine with option, the drive doesn't show up as selection. The really odd part is the drive does work if plugged in with the USB cable!

The drive in question DOES work as expected on my 5th gen MBP with firewire. Further, I can stert my MBP in target disc mode and it will function as expected as a bootable external drive for his machine. The system in question was cloned with Carbon Copy Cloner. And again, it boots from my MBP.

I've tried different sets of cables (even though everything works on my system). I actually had him send the drive back for warranty replacement but of course the new one behaves the same way.

What could be the cause of apparently certain firewire drives not being bootable (but otherwise working) on a 3rd gen MBP? The intended workflow is to be studio/audio work so using the USB connection for a workaround would not be an option.

Any clues? Windows is not even installed on any of these machines!

[jmiddel]

I suspect that the WD needs a bit more current from FW than the latter can give, so it may not be able to function as a boot drive. Your MBP in T-mode works, so maybe another external might be called for.

[CharlesS]

WD may be using a shoddy FireWire bridge. With FireWire, I always liked to get a good Oxford-powered enclosure, although these days, with FireWire being phased out, it probably doesn't matter anymore.