Does frequent rebooting harm a computer?

[casioculture]

I switch off my computer twice a day or so because I do not use it for
many hours and would do well to save the electricity. I opted for a
fast computer with a huge display instead of one I could just leave on.
Anyhow, I know how much a computer costs me per day so let's not argue
over it, because I had measured it and multiplied and know what I want
with the current setup I have.

The question is, does frequent rebooting harm a computer? The reason I
ask is that now I'm considering a linux livecd so that I could do some
work with it without the distraction of my regular installation of
windows. I would not be able to get online with a linux livecd (let's
not argue over it, i won't on my computer) so there's no web or instant
messaging, no movies, and all I could do is edit text like I should be
doing.

Would 4 or 5 reboots per day harm a computer? In particular, the hard
drives? or is it somewhat harmless?

By rebooting i mean orderly rebooting, from clicking shut-down in
software, not switching the thing off from the mains or pushing reset.

 

[nog]

I switch off my computer twice a day or so because I do not use it for
many hours and would do well to save the electricity. I opted for a
fast computer with a huge display instead of one I could just leave on.
Anyhow, I know how much a computer costs me per day so let's not argue
over it, because I had measured it and multiplied and know what I want
with the current setup I have.

The question is, does frequent rebooting harm a computer? The reason I
ask is that now I'm considering a linux livecd so that I could do some
work with it without the distraction of my regular installation of
windows. I would not be able to get online with a linux livecd (let's
not argue over it, i won't on my computer) so there's no web or instant
messaging, no movies, and all I could do is edit text like I should be
doing.

Would 4 or 5 reboots per day harm a computer? In particular, the hard
drives? or is it somewhat harmless?

By rebooting i mean orderly rebooting, from clicking shut-down in
software, not switching the thing off from the mains or pushing reset.

You can only answer questions like this when considering samples of many
systems, and arriving at historical conclusions.
In the case of your own system, barring a single catastrophic event, or
obviously unfavourable operating conditions, you'll probably never know
exactly which factors resulted in whatever its lifespan - or that of any of
its components - turns out to be.
That said, power cycling is generally considered to be one of the more
rigorous events, particularly in respect of HDD opoeration.

 

[Mxsmanic]

I switch off my computer twice a day or so because I do not use it for
many hours and would do well to save the electricity. I opted for a
fast computer with a huge display instead of one I could just leave on.
Anyhow, I know how much a computer costs me per day so let's not argue
over it, because I had measured it and multiplied and know what I want
with the current setup I have.

There is no problem with shutting down a computer if you don't plan to
use it for several hours. Be sure you shut down Windows before you
turn the power off, though (don't just flick the switch). Some
systems will shut down Windows when you press the power button
automatically.

The question is, does frequent rebooting harm a computer?

It subjects the computer to thermal stresses and puts some wear on
mechanical components such as disk drives and fans. There's a
breakeven point at which it's better to keep the machine on than it is
to turn it off, but it's extremely difficult to calculate that exact
point. Clearly, if you don't plan to use the computer for a week,
it's best to turn it off, and if you plan to use it ten minutes from
now, it's best to leave it on; but it's hard to say where the
breakeven point falls between those two extremes.

The reason I
ask is that now I'm considering a linux livecd so that I could do some
work with it without the distraction of my regular installation of
windows. I would not be able to get online with a linux livecd (let's
not argue over it, i won't on my computer) so there's no web or instant
messaging, no movies, and all I could do is edit text like I should be
doing.

Would 4 or 5 reboots per day harm a computer? In particular, the hard
drives? or is it somewhat harmless?

Rebooting _without turning the power off_ is pretty harmless, since
there is no thermal shock and all the mechanical parts continue to
run. If your monitor powers down while the machine reboots, it might
put a tiny bit of wear on that, particularly if it's a CRT.

By rebooting i mean orderly rebooting, from clicking shut-down in
software, not switching the thing off from the mains or pushing reset.

The only thing that matters from a wear-and-tear standpoint is turning
the machine off and on again (power cycling); software shutdowns and
resets are quite harmless to the PC (but see the comment on monitors
above).

 

[John Doe]

I switch off my computer twice a day or so because I do not use it
for many hours and would do well to save the electricity. I opted
for a fast computer with a huge display instead of one I could
just leave on.

So just turn off the monitor.

The question is, does frequent rebooting harm a computer? ...
Would 4 or 5 reboots per day harm a computer? In particular, the
hard drives? or is it somewhat harmless?
By rebooting i mean orderly rebooting, from clicking shut-down in
software, not switching the thing off from the mains or pushing
reset.

You can guess there is significant wrenching torque on the spindle
of an HDD when power is first applied. You could ask a manufacturer
or ask in the storage group.

 

[John Doe]

(e-mail address removed) writes:
....

The only thing that matters from a wear-and-tear standpoint is
turning the machine off and on again (power cycling); software
shutdowns and resets are quite harmless

I think he's talking about shutting down through windows, a power
cycle.

 

[kony]

I switch off my computer twice a day or so because I do not use it for
many hours and would do well to save the electricity. I opted for a
fast computer with a huge display instead of one I could just leave on.
Anyhow, I know how much a computer costs me per day so let's not argue
over it, because I had measured it and multiplied and know what I want
with the current setup I have.

The question is, does frequent rebooting harm a computer?

No a HDD's expected lifespan is longer than the prudent
replacement interval regardless of whether you reboot a few
times a day or not. Being a mechanical device, it will
wear the drive a little bit more, but not much for a typical
system, there can be no clear prediction of the specific
failure mode in advance and thus no reasonable expectation
that a few reboots a day will matter. This assumes the
"prudent replacement interval", which should be no longer
than 3 years, and does not displace making regular backups.

However your rebooting will use more power (if a warm reboot
to another OS) than just leaving the most functional OS
running.

IMO, you should consider setting the system to hibernate and
at that point, having it turn off the monitor. No need to
boot to linux live at all if max power savings is the
primary goal.

 

[Stephen Howard]

I switch off my computer twice a day or so because I do not use it for
many hours and would do well to save the electricity. I opted for a
fast computer with a huge display instead of one I could just leave on.
Anyhow, I know how much a computer costs me per day so let's not argue
over it, because I had measured it and multiplied and know what I want
with the current setup I have.

The question is, does frequent rebooting harm a computer? The reason I
ask is that now I'm considering a linux livecd so that I could do some
work with it without the distraction of my regular installation of
windows. I would not be able to get online with a linux livecd (let's
not argue over it, i won't on my computer) so there's no web or instant
messaging, no movies, and all I could do is edit text like I should be
doing.

Would 4 or 5 reboots per day harm a computer? In particular, the hard
drives? or is it somewhat harmless?

By rebooting i mean orderly rebooting, from clicking shut-down in
software, not switching the thing off from the mains or pushing reset.

It sounds pretty much like my pattern of usage - although my reasons
for rebooting are due to swapping out of hard drives in removeable
caddies. I can't say as I've noticed any particular problems.

Might it not be an idea to consider setting up a dual boot system?
Rather than the hassle of booting from a linux cd ( which, over a
period of time, is going to use more energy ) it's a relatively simple
matter to use a boot manager, such as XOSL, to install another OS ( be
it Linux, DOS, Windows etc ).

DOS seems like a good idea if text editing is all you need - there are
plenty of old but decent DOS text editors about, and without all the
hassle of that shutdown malarkey you could be in, out and off in a
fraction of the time it takes for a more complex OS to sort itself
out.

Either that, or a secondary Windows installation heavily geared
towards power saving.

Regards,

 

[Johannes]

I switch off my computer twice a day or so because I do not use it for
many hours and would do well to save the electricity. I opted for a
fast computer with a huge display instead of one I could just leave on.
Anyhow, I know how much a computer costs me per day so let's not argue
over it, because I had measured it and multiplied and know what I want
with the current setup I have.

Yes, you shouldn't leave electrical equipment running unsupervised. A fan
could get stuck leading to overheating.

The question is, does frequent rebooting harm a computer? The reason I
ask is that now I'm considering a linux livecd so that I could do some
work with it without the distraction of my regular installation of
windows. I would not be able to get online with a linux livecd (let's
not argue over it, i won't on my computer) so there's no web or instant
messaging, no movies, and all I could do is edit text like I should be
doing.

Would 4 or 5 reboots per day harm a computer? In particular, the hard
drives? or is it somewhat harmless?

It may shorten the life of the hard drive, but I never think about it
when I switch off my computer. I switch off if I leave for more than
an hour. So far so good.

By rebooting i mean orderly rebooting, from clicking shut-down in
software, not switching the thing off from the mains or pushing reset.

That shouldn't make any difference.

 

[George Woodbine]

Yes, you shouldn't leave electrical equipment running unsupervised. A fan
could get stuck leading to overheating.

So you'll get a waft of a burning smell and the supply will shut down,
this is no big deal. Hardly a reason to power off three or four times a
day. What about other household equipment that gets left to run
unsupervised? Washing machines, frdiges, heating etc?

The chances of your PC's fan buggering up are far increased by power
cycling. Fans like continuous use best, not constant stopping and starting.

 

[Johannes]

So you'll get a waft of a burning smell and the supply will shut down,
this is no big deal. Hardly a reason to power off three or four times a
day. What about other household equipment that gets left to run
unsupervised? Washing machines, frdiges, heating etc?

The chances of your PC's fan buggering up are far increased by power
cycling. Fans like continuous use best, not constant stopping and starting.

Look, do what you want. Everybody is different. A fire is rare, but there
is always a reason, and it's often electrical. I've come across a smouldering
computer, and a smouldering TV which I was very lucky to discover in time.
Hence once burned...

 

[Conor]

Would 4 or 5 reboots per day harm a computer? In particular, the hard
drives? or is it somewhat harmless?

No. THere are people on both sides of the fence who will argue until
the world ends that they are right. The simple fact is that for Joe
Average, it'll make no difference with the computer being upgraded or
changed long before any damage becomes apparent.

 

[meow2222]

I switch off my computer twice a day or so because I do not use it for
many hours and would do well to save the electricity. I

The question is, does frequent rebooting harm a computer?

Would 4 or 5 reboots per day harm a computer? In particular,

The answer is no, it makes no significant difference. People are
discussing minutiae here, and it seems not putting them into
perspective. Practically speaking its a non issue.

You'll save more power when text editing if you arrange some means of
quickly and easily undercloking the system: text editing runs fine on a
233, and adequately on a 66MHz CPU, so unless you're using a dinosaur
you can throttle right back. I dont know of any software that will
change pc speed quickly and easily, maybe someone else does. (I did
play with one 4 years or so back, but whether that works on modern PCs
I havent a clue.) I suppose a crystal switch might possibly do it, and
divide speed by eg 10. Doing it that way would slow almost every data
path in the system down, hugely cutting pwoer use, and probably you'd
be able to switch the fans off too. Fancy a nearly no run cost machine?


Now if you want to wallow in pedantry, we could look at the lifetime
effect of power cycling on a CRT. The nearest item for which I do have
data is a T12 halophosphate fluorescent tube, which has a somewhat
similar emitter, the most vulnerable bit, and a life time of 20,000
hours if frequently switched in a glow start system, and 30,000 if not
switched, or switched electronically.

TVs use indirect emitters, which are much longer lasting, and much less
vulnerable to switch on surge, because firstly they run at lower temps,
secondly theyre heatsinked to some extent, so greater thermal mass, and
thirdly theyre not directly exposed to ionic bombardment, since Tv
tubes use an ion trap.

TVs use electronic heater supplies, with no startup boost, so theyre
closer to electronic fl fittings than glow start. Glows apply a large
over-power to the filaments during startup.

So you should get 30,000 hours either way. If you leave it on 24/7,
that would give you an average tube life of: 3.5 yrs. Thats if, and its
a somewhat questionable assumption, if CRT life equals T12 tube life.
Since its direct vs indirect emitter, I thaink thats most unlikely, and
the CRT would last many times as long.

OTOH if you used the CRT 6hrs a day, that would be a 14 yr life, or
several times that since its an indirect emitter.

This roughly lines up with what I've seen with TVs, ie that tubes
normally do 20 years with no problem in domestic use, but a minority do
deteriorate to some extent. Only rarely do they fail in that time. This
might line up with a - wave wet finger in air - perhaps 60 year average
life.


If I'd thought about this before writing, I wouldnt have written. Life
has bigger things.


NT

 

[JAD]

So you'll get a waft of a burning smell and the supply will shut down,
this is no big deal. Hardly a reason to power off three or four times a
day. What about other household equipment that gets left to run
unsupervised? Washing machines, frdiges, heating etc?

Best scenario, yep smoke and then nothing, but then maybe each peripheral
getting masticated as voltages go wild.
Best reason to shut down...power costs why give your money to ENRON? Never
leave a washer running unsupervised, thats double jeapardy,, water and
eletrical, the damage is unpredictable.

The chances of your PC's fan buggering up are far increased by power
cycling. Fans like continuous use best, not constant stopping and

starting.

You talk to your fans?

 

[Roger Hunt]

On Sun, 2 Oct 2005, typed this :
(snip)

Would 4 or 5 reboots per day harm a computer? In particular, the hard
drives? or is it somewhat harmless?

Somewhat harmless, unless power is turned back on before the drives have
spun down, (as I discovered once as an inductor burned out).

For interest's sake HDDHealth (free) may be worth installing :
http://www.panterasoft.com/

Gives all sorts of info about installed hard drives and monitors
performance. It also reports power on cycles and total power-up time for
each drive (for my fairly new Maxtor and WD drives - the info must be
stored on the drive somewhere).

 

[w_tom]

Yes, frequent power down does damage. Then we review those
numbers. A switch is rated for 100,000 cycles. That is power
cycling seven times every day for ... 38 years. The lowest
number I ever saw for a disk drive was 40,000 power cycles:
seven times every day for ... 15 years. So power cycling is
destructive. And when we put numbers to those claims. No one
(who first learns facts) cares. It's called the perspective
of reality.

That is the point. Those who worry about damage from power
cycling also do not use numbers. It is also called junk
science reasoning or propaganda. If power cycling was
destructive, then we would also leave on TVs and automobiles.

Turn it off when done - and ignore others who worry about
minutiae ... because they never bother to first learn the
numbers. There is no debate. Too many just know power cycling
must be destructive without first learning facts - the
numbers.

 

[cpliu]

Anyhow, I know how much a computer costs me per day so let's not argue
over it, because I had measured it and multiplied and know what I want
with the current setup I have.

Could you share with us your findings on cost?

Thanks,

cpliu

 

[John Weiss]

Would 4 or 5 reboots per day harm a computer? In particular, the hard
drives? or is it somewhat harmless?

By rebooting i mean orderly rebooting, from clicking shut-down in
software, not switching the thing off from the mains or pushing reset.

A "soft" reboot won't harm anything. The HDs don't spin down, the PS doesn't
cycle...

 

[if]

Yes, frequent power down does damage. Then we review those
numbers. A switch is rated for 100,000 cycles. That is power
cycling seven times every day for ... 38 years. The lowest
number I ever saw for a disk drive was 40,000 power cycles:
seven times every day for ... 15 years. So power cycling is
destructive. And when we put numbers to those claims. No one
(who first learns facts) cares. It's called the perspective
of reality.

That's pretty much what I've found. I use pretty aggressive power saving,
with disks spinning down after 1/2 an hour idle time (mainly to reduce
noise), and SMART monitoring shows I've probably cut the life of the disks
from 20 years to 10 years as a result. However I've never kept a drive for
more than 4 years before it had to be retired to make way for a bigger one,
so a 10 year projected life is more than enough.

With my CRT monitor it's a similar story. After 7 years and an est. 20,000
hours in use the horizontal deflection is playing up, probably due to
thermal stress of frequently going in and out of standby (I had it set to
go into standby after 10 minutes idle time). I've had to disable the
monitor's power saving because of this, but on the upside I've probably
saved about £150 in electricity over the period by having the monitor going
into standby mode whenever it's idle, which is enough to pay for another
17" trinitron at today's prices.

One thing to avoid, as another poster said, is turning disks on again
before they've finished powering down. I once stupdily powercycled my
machine several times in a row at 5 second intervals to try and fix some
startup glitch I was having and after about six attempts the BIOS reported
primary HD failure. Luckily it came back to life after a couple of hours
and has been fine since (except for some bad blocks, but then it's an IBM
Deathstar of the dodgy generation) but it gave me a big shock.

 

[if]

Could you share with us your findings on cost?

The way I work such things out is find out how much electricity the
computer uses and then work out how much might be saved by putting either
the monitor or system as a whole into standby mode (or turning it off
completely) whenever possible. Multiply that up for the expected life of
the computer.

Set against that is the cost of the shortened life of the computer due to
startup stress. This is harder to estimate, but unless you are trying to
get your machine to last for 20 years, it's likely that you would have
already replaced it well before that point, in which case this cost is
free. If you intend to replace your computer within 5 years I would not
even bother trying to calculate it.

As I mentioned in another post, my own estimate is that on monitor power
saving I have saved enough on electricity over 7 years to pay for a
replacement monitor of the same type. Had I not used power saving, I doubt
it would have lasted a further 7 years (I would have replaced it for some
snazzy flatscreen well before that anyhow), so overall I've won out.

One thing that amazes me is how some people leave even their
computers and even monitors running 24 hours a day without any power
saving. Just leaving a 17" CRT on overnight is going to cost you about £50
a year in extra electricity, which is around 1/2 the cost of that device
(depending on how good a CRT it is). A similar case can be made against
people who leave their system box running 24hrs/day, e.g. to do SETI work -
the cost of this could easily be another £50/year in electricity compared
to letting your CPU idle when not in use, and putting it in standby
whenever the computer is not needed for an hour or two.

 

[kony]

One thing that amazes me is how some people leave even their
computers and even monitors running 24 hours a day without any power
saving. Just leaving a 17" CRT on overnight is going to cost you about £50
a year in extra electricity, which is around 1/2 the cost of that device
(depending on how good a CRT it is). A similar case can be made against
people who leave their system box running 24hrs/day, e.g. to do SETI work -
the cost of this could easily be another £50/year in electricity compared
to letting your CPU idle when not in use, and putting it in standby
whenever the computer is not needed for an hour or two.

One thing that amazes me is that people try to make sweeping
assumptions about power usage of devices that don't have
static current.

There are simple things one can do IF they decide they're
going to leave their monitor fully on, like using a blanked
black screensaver, that quite significantly reduce power
consumption. It must be put in perspective though... Do you
pack additional insulation around your refridgerator to save
$ on it's energy usage? Do you always turn off all lights
in your house then turn down the brightness on your TV to
save on it's power? In the cooler months of the year, do
you recognize that the power used by a computer is heating
the room so there could be a lower HVAC utilization if you
plan for that?

Things have to be put in perspective.