[drcarl]

I currently have an iMac 800MHz with Firewire 400 and only USB 1.1.

The iMac's current hard drive is getting full and I'm considering buying an external hard drive. My main question is: Is it necessary to physically switch off an external hard drive when you are done using it?

Here's a related question: Would I notice a speed improvement by booting off the external drive vs the internal drive?

[icruise]

It's not necessary to turn it off -- most drives will spin down after a period of inactivity anyway.

I doubt if you'd see a big difference booting off an external drive, but if you only have 5400rpm internal disk and used a 7200rpm external disk, you may see some difference. But if you plan to use firewire for other things like capturing video or burning CDs/DVDs, you might run into bandwidth problems by using an external disk as your startup disk.

[angelmb]

Once you are done using it, just unmount it and the drive would spin down. That easy.

[icruise]

Yes, but what I'm saying is that you don't have to unmount it either. I leave my external disks on all the time and they spin down after not being used for a certain amount of time. When I use something that accesses them, they spin up again.

[drcarl]

I believe the internal drive is 5400 rpm and the external drive would be 7200 rpm. I do some digital video via firewire. The iMac has 2 firewire ports. If I used one port for the 7200 rpm drive as the boot volume and the other port for the camcorder, would there be a slowdown?

[Big Mac]

Since your Mac only has one Firewire bus servicing both ports (all Macs that I know of only have one Firewire bus), I'd agree it's not the best idea to boot from the external drive.

[bojangles]

Is it necessary to physically switch off an external hard drive when you are done using it?

That depends… how much electricity do you want to save? I have three Firewire drives that I use to back up the internal: a 320GB that stores my nightly backup, plus a 2×160GB striped RAID that stores my weekly backup (set to run early Saturday morning). The daily backup drive stays on 24/7 and spins down whenever it’s not in use (which is much of the time), but since the weekly backup only gets used once a week, I switch both of its drives on, every Friday night before bed. Whenever I happen by on Saturday and see that the backup is complete, I unmount the RAID and switch both drives back off.

Caveat: I know you’re talking about using the external drive for additional storage (as opposed to backup), but note that unless you tell it to do otherwise, having a backup drive switched on 24/7 causes Spotlight to find everything twice, with no easy way to tell which is which. Just an FYI….

[Leonard]

Depends. Will you use it all the time? Do you power down your computer? If you use it like a backup drive, like Bojangles and I, we generally unmount it and power it off when not in use. If your going to leave it mounted and connected to the iMac all the time because you have your applications or games on it and you power down the computer, the general rule is you power everything up before the computer and power everything down after the computer is powered down. In the case of firewire drives, though, you can unmount and power them down anytime, just make sure you unmount it first or you could (will) have problems.

I use firwire drive to backup and archive files every month or two. I connect and mount it when I'm doing the backup, and unmount it and disconnect it when the backup is done.