How much "rest" does an external HD need?

GanChan

macrumors 6502a
Original poster
Jun 21, 2005
590
24
I have a new Western Digital 80G external drive (39 bucks after rebate from CC, couldn't resist), and I'm wondering how anal I should be about powering it down at the end of each day or work session, like I do with my primary hard drive. The reason I ask is, after I un-mount the drive from my desktop, the drive stays on; pushing the Power button makes the button blink a few times, but it doesn't actually power off until I detach the AC cable.

:confused:
 

aussie_geek

macrumors 65816
Apr 19, 2004
1,093
0
Sydney Australia
GanChan said:
I have a new Western Digital 80G external drive (39 bucks after rebate from CC, couldn't resist), and I'm wondering how anal I should be about powering it down at the end of each day or work session, like I do with my primary hard drive. The reason I ask is, after I un-mount the drive from my desktop, the drive stays on; pushing the Power button makes the button blink a few times, but it doesn't actually power off until I detach the AC cable.

:confused:
Drive manufacturers publish various specs on their drives. One is 'Start Stop Cycles'. This is the number of times the disk can be started up from zero RPM to operating RPM. A typical drive has an expected minimum of 50,000 start stop cycles.

So, theoretically the more times you stop / start your drive, you are wearing it out.

But then on the other hand, maybe the disk motors / bearings will wear out sooner on a drive that is rotating constantly. One or the other will happen over time.

But we are talking years worth of HD activity for these drive failure symptoms to develop. The way I see it, it's totally up to you - there are no pro's or cons regarding leaving a disk on.

The most damage to a disk is done during a read / write and the power goes out. The drive heads can hit the platter and eat it!!

More to read here


aussie_geek
 

jalagl

macrumors 6502a
Jun 5, 2003
802
1
Costa Rica
Mine is ON all the time I have my laptop at my desk, including at night.
Has been like that for over a year now, with no significant sign of problems.

Hope it stays that way for a while...
 

Jigglelicious

macrumors 6502
Apr 25, 2004
421
0
NYC
Allowing a hard drive to spin constantly is better for it than constantly shutting it off and turning it on, which wears it out quickly. This is one of the primary reasons why the "Put hard disk to sleep" feature in OS X can actually be more harmful than helpful, and its one of the first things I turn off on a fresh copy of OS X.
 

wdlove

macrumors P6
Oct 20, 2002
16,570
0
I leave my external Mercury OWC Elite HD on all the time. Except to turn it off when doing a major upgrade like 10.3.9. I have been doing this for over two years now, no problems. So I guess that I will see in another year or two how this works out.
 

Scarpad

macrumors 68000
Jan 13, 2005
1,881
366
Ma
wdlove said:
I leave my external Mercury OWC Elite HD on all the time. Except to turn it off when doing a major upgrade like 10.3.9. I have been doing this for over two years now, no problems. So I guess that I will see in another year or two how this works out.

I have that same drive are'nt you concerned about heat? It's a fanless case, sure it's aluminum but then it's encased in ventless plastic and it dows get warm/hot. I'm going to start leaving mine on but then have it go to sleep when not in use, otherwise I think Heat will kill it first. I might seek a fan alternative