to power off / not power off external hard drive???

Chuck Jeanneret

macrumors newbie
Original poster
Aug 17, 2007
Hi all! I am a switcher going on about a month now and getting settled in.

Question about external hard drives: I've read in posts that people never power off their external HD, and that the constant on/off actually damages the HD. Is this true? Can't remember where I've read it cuz I've been reading so much in these and other forums lately.

I am running a MBP, and I power off the MBP when I'm not using it. If the answer is that I shouldn't power off my external HD, can I do that even if I power down my MBP?

Thanks in advance for the answers, and thanks to all you guys in this forum for helping me through my early Mac days (and I suspect my later ones too).


Moderator emeritus
Aug 16, 2005
I personally don't turn my external HDs off. It's hooked up to my MacBook and even when I close it or take it with me my external HD keeps running, though obviously doing nothing. I usually forget about it. Turning it on and off on a frequent basis can potentially be hard on it, but generally not an issue. Maybe more an issue with generic drives.

jihad the movie

macrumors regular
Jun 18, 2003
Smugtown, NY
I've wondered the same thing. I had a Western Digital external about four years ago that I would only use when I needed it, and I would turn it off when I didn't need it. The enclosure died after two years of use, but the drive was okay. I have always wondered if turning it on and off was what killed it. I have a Lacie D2 right now, and I have been debating what is the best procedure for it.


Jul 11, 2006
I only turn mine off when I turn my computer of for more than a day, which is maybe once a month, sometimes longer.


macrumors regular
Jul 25, 2007
Wisconsin der hey
i have a WD MyBook connected to my windows machine and it turns off when the computer turns off and on when it turns on.

it has all my pictures + backup data. if i don't need my pictures or the drive for that matter, i just leave it off (partly bc windows can get confused sometimes... okay, a lot ;) )

it's all a matter of preference really.
if you think about it, you only turn your Mac's drive off when you turn the computer off.