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Are disk bearings really harmed by spin-up?

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Anonymous
a b G Storage
May 13, 2005 12:21:52 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

I have seen various comments like "we leave our servers running 24/7
because powering up a hard drive causes more wear than leaving it
running." I think it's mostly laziness and apathy about conserving
energy. The TiVo forums discuss it a lot because a standard TiVo HD
runs all the time, buffering 30 minutes of whatever channel it's left
on.

Do IT people who leave servers running 24/7 ever have much choice of
NOT leaving them on 24/7? If not, how can they make scientific
comparisons of drive-bearing life? As long as the head isn't moving,
bearing life seems to be the main concern. On a home PC left on all day
it's far less likely that the drive will be doing anything but spinning
at high RPM for no real reason.

I've heard similar claims that the "shock" of turning on a light bulb
is worse than leaving it on all the time. Usually those comments came
as a way to excuse energy consumption after a debate on the merits of
waste. In reality, bulbs have a finite hours rating and will burn out
faster the longer they are left on, as long as they aren't flipped on
and off as torture. CFL bulbs (w/ballast) don't like to be switched on
and off quickly, but I can't imagine them burning out faster if you
only cycle on/off once in 10 minutes or so.

Would anyone claim that car wheel bearings get as much wear when you
pull out of the driveway vs. a 500 mile nonstop trip? In that case, the
"spin up" would be when you first move the car after sitting. What
exactly causes the "big shock" when a hard drive spins up? The heat
generated from constant spinning would seem to far outweigh it. Why
does Windows have a "Turn off hard disks" feature in Power options if
not to reduce bearing wear?

If anyone has thorough technical articles on hard drive wear, please
post. Specifically, what is so torturous about spinning up the drive,
and how can that brief cycle be quantified, damage-wise against
constant spinning with higher heat levels?

Thanks.

JT
Anonymous
a b G Storage
May 13, 2005 6:21:56 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

my observations of the newer ata drives in the last year was they succumb
easily to heat than constant booting. I had a server that run 24/7 for weeks
and some of the drives needed to be replaced every few months. Much faster
than other computers that shutdown in the same environment. It could also be
because of the cheap maxtor plus 8 the raid was using, hard to tell but keep
those drives cool I say.


"Jack Tyler" <jctyler_67@yahoo.com> wrote in message
news:1115954512.453949.223990@g49g2000cwa.googlegroups.com...
>I have seen various comments like "we leave our servers running 24/7
> because powering up a hard drive causes more wear than leaving it
> running." I think it's mostly laziness and apathy about conserving
> energy. The TiVo forums discuss it a lot because a standard TiVo HD
> runs all the time, buffering 30 minutes of whatever channel it's left
> on.
>
> Do IT people who leave servers running 24/7 ever have much choice of
> NOT leaving them on 24/7? If not, how can they make scientific
> comparisons of drive-bearing life? As long as the head isn't moving,
> bearing life seems to be the main concern. On a home PC left on all day
> it's far less likely that the drive will be doing anything but spinning
> at high RPM for no real reason.
>
> I've heard similar claims that the "shock" of turning on a light bulb
> is worse than leaving it on all the time. Usually those comments came
> as a way to excuse energy consumption after a debate on the merits of
> waste. In reality, bulbs have a finite hours rating and will burn out
> faster the longer they are left on, as long as they aren't flipped on
> and off as torture. CFL bulbs (w/ballast) don't like to be switched on
> and off quickly, but I can't imagine them burning out faster if you
> only cycle on/off once in 10 minutes or so.
>
> Would anyone claim that car wheel bearings get as much wear when you
> pull out of the driveway vs. a 500 mile nonstop trip? In that case, the
> "spin up" would be when you first move the car after sitting. What
> exactly causes the "big shock" when a hard drive spins up? The heat
> generated from constant spinning would seem to far outweigh it. Why
> does Windows have a "Turn off hard disks" feature in Power options if
> not to reduce bearing wear?
>
> If anyone has thorough technical articles on hard drive wear, please
> post. Specifically, what is so torturous about spinning up the drive,
> and how can that brief cycle be quantified, damage-wise against
> constant spinning with higher heat levels?
>
> Thanks.
>
> JT
>
May 13, 2005 8:31:34 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

"Jack Tyler" <jctyler_67@yahoo.com> wrote in news:1115954512.453949.223990
@g49g2000cwa.googlegroups.com:

> I have seen various comments like "we leave our servers running 24/7
> because powering up a hard drive causes more wear than leaving it
> running." I think it's mostly laziness and apathy about conserving
> energy. The TiVo forums discuss it a lot because a standard TiVo HD
> runs all the time, buffering 30 minutes of whatever channel it's left
> on.
>
> Do IT people who leave servers running 24/7 ever have much choice of
> NOT leaving them on 24/7? If not, how can they make scientific
> comparisons of drive-bearing life? As long as the head isn't moving,
> bearing life seems to be the main concern. On a home PC left on all day
> it's far less likely that the drive will be doing anything but spinning
> at high RPM for no real reason.
>
> I've heard similar claims that the "shock" of turning on a light bulb
> is worse than leaving it on all the time. Usually those comments came
> as a way to excuse energy consumption after a debate on the merits of
> waste. In reality, bulbs have a finite hours rating and will burn out
> faster the longer they are left on, as long as they aren't flipped on
> and off as torture. CFL bulbs (w/ballast) don't like to be switched on
> and off quickly, but I can't imagine them burning out faster if you
> only cycle on/off once in 10 minutes or so.
>
> Would anyone claim that car wheel bearings get as much wear when you
> pull out of the driveway vs. a 500 mile nonstop trip? In that case, the
> "spin up" would be when you first move the car after sitting. What
> exactly causes the "big shock" when a hard drive spins up? The heat
> generated from constant spinning would seem to far outweigh it. Why
> does Windows have a "Turn off hard disks" feature in Power options if
> not to reduce bearing wear?
>
> If anyone has thorough technical articles on hard drive wear, please
> post. Specifically, what is so torturous about spinning up the drive,
> and how can that brief cycle be quantified, damage-wise against
> constant spinning with higher heat levels?

You posted from google groups...so what did the archive say about the past
discussions on this topic?

--
Minister of All Things Digital & Electronic, and Holder of Past Knowledge
stile99@email.com. Cabal# 24601-fnord | Sleep is irrelevant.
I speak for no one but myself, and |Caffeine will be assimilated.
no one else speaks for me. O- | Decaf is futile.
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Anonymous
a b G Storage
May 13, 2005 12:24:53 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

> Many drives are now using
> hydrostatic bearings, which will eliminate *some* of the low pressure
> problem at startup depending on how the pressure is supplied.

BTW, just to be clear, hydrostatic bearings are used in HDD's to reduce
noise, not to extend bearing life.

Randy S.
Anonymous
a b G Storage
May 13, 2005 6:40:36 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

More than continuing to spin, yes.

There's a reason for the number of start stop
cycles specified in the hard drive datasheets.

Jack Tyler <jctyler_67@yahoo.com> wrote in message
news:1115954512.453949.223990@g49g2000cwa.googlegroups.com...

> I have seen various comments like "we leave our
> servers running 24/7 because powering up a hard
> drive causes more wear than leaving it running."

That is correct.

> I think it's mostly laziness

Nope.

> and apathy about conserving energy.

Yep, what a hard drive uses is a fart in the bath, 5W or so.

> The TiVo forums discuss it a lot because a standard TiVo HD runs
> all the time, buffering 30 minutes of whatever channel it's left on.

> Do IT people who leave servers running 24/7 ever
> have much choice of NOT leaving them on 24/7?

Yes, the drives can be configured to spin down on inactivity.

> If not, how can they make scientific
> comparisons of drive-bearing life?

There's a reason for the limit to start stop cycles
in the hard drive manufacturer's data sheets.

> As long as the head isn't moving, bearing
> life seems to be the main concern.

You dont get many hard drives bearings failing anymore.

> On a home PC left on all day it's far less likely that the drive will
> be doing anything but spinning at high RPM for no real reason.

Sure.

> I've heard similar claims that the "shock" of turning
> on a light bulb is worse than leaving it on all the time.

That can be overstated, but there certainly is a considerable turnon
shock with incandescent bulbs. Not relevant to hard drives tho.

> Usually those comments came as a way to excuse energy
> consumption after a debate on the merits of waste.

Sure.

> In reality, bulbs have a finite hours rating and
> will burn out faster the longer they are left on,
> as long as they aren't flipped on and off as torture.

Sure, but irrelevant to hard drives.

> CFL bulbs (w/ballast) don't like to be switched on and
> off quickly, but I can't imagine them burning out faster
> if you> only cycle on/off once in 10 minutes or so.

Yes, the turnon effect is completely different to incandescent bulbs.

> Would anyone claim that car wheel bearings get as much wear
> when you pull out of the driveway vs. a 500 mile nonstop trip?

Completely different to hard drives.

> In that case, the "spin up" would be
> when you first move the car after sitting.

And that is completely different to a hard drive.

> What exactly causes the "big shock" when a hard drive spins up?

Basically the spinup torque.

> The heat generated from constant
> spinning would seem to far outweigh it.

Anyone with a clue ensures that the drive doesnt get hot.

> Why does Windows have a "Turn off hard disks"
> feature in Power options if not to reduce bearing wear?

To reduce power used, just like with monitors and motherboards.

> If anyone has thorough technical articles
> on hard drive wear, please post.

The start stop cycles specified in the hard drive datasheets
are the most imporant numbers. They can be exceeded by
a startup every hour surprisingly quickly.

> Specifically, what is so torturous about spinning up the drive,
> and how can that brief cycle be quantified, damage-wise
> against constant spinning with higher heat levels?

Thermal cycling also isnt good for most electronic devices.
Anonymous
a b G Storage
May 14, 2005 3:51:18 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Fri, 13 May 2005 08:17:45 -0400, rswittNO@SPAMgmail.com suggested:
:
: Why is it up to the IT people to do the scientific comparisons, isn't
: that up to the manufacturer? As an IT person who *also* used to design
: bearings (ball, journal *and* roller) there *are* both wear and startup
: issues. Most catastrophic failures occur at startup unless there is an
: unrelated cause of failure (like an overheat condition, overloading or
: oil starvation).

One trick that the systems guy where I work has told me about is that
before he deploys a server, he frequently powers it on and off over the
course of a week or two to try to get any marginal hard disks to fail (and
then replace them) before it goes into live use.

--
agreenbu @ nyx . net andrew michael greenburg
Anonymous
a b G Storage
May 14, 2005 5:09:47 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Jack Tyler wrote:

> I have seen various comments like "we leave our servers running 24/7
> because powering up a hard drive causes more wear than leaving it
> running."

This is the conventional wisdom. And it's not just disks. Thermal cycling
used to be a serious problem with computers--that's why memory sockets have
latches now. On an original IBM PC that had been running for a couple of
years, sometimes the memory chips would walk completely out of the socket
due to repeated thermal cycling.

> I think it's mostly laziness and apathy about conserving
> energy.

Shutting down a large server farm is not something to be done lightly.
Bringing it down and back up in an orderly fashion might take more than one
night.

> The TiVo forums discuss it a lot because a standard TiVo HD
> runs all the time, buffering 30 minutes of whatever channel it's left
> on.

Yep, and they seem to last and last.

> Do IT people who leave servers running 24/7 ever have much choice of
> NOT leaving them on 24/7?

Depends on the circumstances.

> If not, how can they make scientific
> comparisons of drive-bearing life?

The viewpoint is generally based on experience with other mechanical
devices.

> As long as the head isn't moving,
> bearing life seems to be the main concern.

Even if the head is moving, bearing life is the main concern as far as
_wear_ goes. The heads run on an air bearing--the wear is negligible.

However disk seldom die of bearing failure--generally the failure is a crash
or an electronics failure.

> On a home PC left on all day
> it's far less likely that the drive will be doing anything but spinning
> at high RPM for no real reason.

Maybe on _your_ system.

> I've heard similar claims that the "shock" of turning on a light bulb
> is worse than leaving it on all the time. Usually those comments came
> as a way to excuse energy consumption after a debate on the merits of
> waste. In reality, bulbs have a finite hours rating and will burn out
> faster the longer they are left on, as long as they aren't flipped on
> and off as torture. CFL bulbs (w/ballast) don't like to be switched on
> and off quickly, but I can't imagine them burning out faster if you
> only cycle on/off once in 10 minutes or so.

You ever notice how light bulbs generally blow when you turn them on, not
when they are just sitting there giving off light? It's called "thermal
shock" and it's a real phenomenon.

> Would anyone claim that car wheel bearings get as much wear when you
> pull out of the driveway vs. a 500 mile nonstop trip? In that case, the
> "spin up" would be when you first move the car after sitting. What
> exactly causes the "big shock" when a hard drive spins up? The heat
> generated from constant spinning would seem to far outweigh it. Why
> does Windows have a "Turn off hard disks" feature in Power options if
> not to reduce bearing wear?
>
> If anyone has thorough technical articles on hard drive wear, please
> post. Specifically, what is so torturous about spinning up the drive,
> and how can that brief cycle be quantified, damage-wise against
> constant spinning with higher heat levels?

The basic problem with any bearing is that at rest the mass supported by the
bearing causes the rotating assembly to sink though the lubricant until it
is touching something solid. When the device of whatever kind is started,
there is a period before the lubricating film reestablishes itself in which
there is metal-to-metal contact. Thus most of the wear occurs at startup.
This is exacerbated by the fact that the lubricant is cold and thus does
not flow well.

The "heat generated from constant spinning", assuming that the drive is not
being operated outside its rated temperature range, has negligible effect
on the durability of the mechanical components--it would have more effect
on the electronics but the electronic components are outside the capsule.

> Thanks.
>
> JT

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)
Anonymous
a b G Storage
May 14, 2005 5:14:06 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Randy S. wrote:

>> Many drives are now using
>> hydrostatic bearings, which will eliminate *some* of the low pressure
>> problem at startup depending on how the pressure is supplied.
>
> BTW, just to be clear, hydrostatic bearings are used in HDD's to reduce
> noise, not to extend bearing life.

Actually, fluid dynamic bearings (they are not "hydrostatic") have sliding
contact at startup, where a ball or roller will normally have rolling
contact unless the lubricant is very stiff. So the FDB will have more wear
at startup.

> Randy S.

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)
Anonymous
a b G Storage
May 14, 2005 6:23:58 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Jack Tyler wrote:

> Would anyone claim that car wheel bearings get as much wear when you
> pull out of the driveway vs. a 500 mile nonstop trip?

Would anyone claim that crankshaft bearings get as much wear when you
start up a cold engine vs. driving for a couple of hours? Yes.
Anonymous
a b G Storage
May 14, 2005 11:55:11 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Joe Smith wrote:

> Jack Tyler wrote:
>
> > Would anyone claim that car wheel bearings get as much wear when
you
> > pull out of the driveway vs. a 500 mile nonstop trip?
>
> Would anyone claim that crankshaft bearings get as much wear when you
> start up a cold engine vs. driving for a couple of hours? Yes.

I understand lubrication phenomena but I'm trying to find a way to
quantify startup wear vs. constant running wear. Maybe it's just hard
to quantify without a lot of guesswork.

JT
Anonymous
a b G Storage
May 14, 2005 11:56:24 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Howard wrote:

> > If anyone has thorough technical articles on hard drive wear,
please
> > post. Specifically, what is so torturous about spinning up the
drive,
> > and how can that brief cycle be quantified, damage-wise against
> > constant spinning with higher heat levels?
>
> You posted from google groups...so what did the archive say about the
past
> discussions on this topic?

Lots of hearsay in past discussions. This thread has been a lot more
informative.

JT
Anonymous
a b G Storage
May 14, 2005 11:59:32 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Rod Speed wrote:

> There's a reason for the number of start stop
> cycles specified in the hard drive datasheets.

I think I need to find and read those datasheets. If you have any quick
links, please post.

JT
Anonymous
a b G Storage
May 14, 2005 12:12:36 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Rod Speed wrote:

> The start stop cycles specified in the hard drive datasheets
> are the most imporant numbers. They can be exceeded by
> a startup every hour surprisingly quickly.

http://www.pcguide.com/ref/hdd/perf/qual/specCycles-c.h...

Well, I'm reading that start/stop cycles are typically in the 30k to
50k range, and that's something I didn't know. I wasn't looking for the
right keywords. One boot per day on a home PC would allow for 109 years
at 40k cycles, which means other components must wear out faster than
bearings! This is the info I needed.

JT
Anonymous
a b G Storage
May 14, 2005 12:14:01 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Thanks for going to the trouble to write all that. I have been
ejumekatud.

JT
Anonymous
a b G Storage
May 14, 2005 12:42:14 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Rod Speed wrote:

> > Would anyone claim that car wheel bearings get as much wear
> > when you pull out of the driveway vs. a 500 mile nonstop trip?
>
> Completely different to hard drives.

In principle it's the same, just with a lot more load on those wheel
bearings. They take a lot of stress when you drive so I question that
pulling out of the garage is significantly worse than a long trip on a
hot day. Cold engine starts are different because oil has to be pulled
up farther from the crankcase, though there's usually film left on the
cylinder walls and crank bearings. Slick 50's claims of metal on metal
are overhyped. But this is getting off topic.

> > Why does Windows have a "Turn off hard disks"
> > feature in Power options if not to reduce bearing wear?
>
> To reduce power used, just like with monitors and motherboards.

Other posters have claimed that power usage is nil but clearly it's
not. My main angle on this was about saving energy. Multiply 5 watts by
millions of computers and you've saved a lot of power. Do that with
countless other gadgets and you've saved a lot more. People leave work
monitors on all weekend (with goldfish tank displays) when they're
gone. Too much trouble to push the off button or let the screen blank
out? Diesel owners idle their engines way too much, etc..

Anything that doesn't have to run 24/7 could be turned off instead of
blaming it all on Kenneth Lay and the Arabs.

JT
Anonymous
a b G Storage
May 14, 2005 1:01:36 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

J. Clarke wrote:
> Randy S. wrote:
>
>
>>>Many drives are now using
>>>hydrostatic bearings, which will eliminate *some* of the low pressure
>>>problem at startup depending on how the pressure is supplied.
>>
>>BTW, just to be clear, hydrostatic bearings are used in HDD's to reduce
>>noise, not to extend bearing life.
>
>
> Actually, fluid dynamic bearings (they are not "hydrostatic") have sliding
> contact at startup, where a ball or roller will normally have rolling
> contact unless the lubricant is very stiff. So the FDB will have more wear
> at startup.

Whoops, for some reason I was thinking "hydrostatic" (which exist but
aren't used in hard disks) instead of Fluid dynamic. Thanks John!

Randy S.
Anonymous
a b G Storage
May 14, 2005 3:46:46 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

> http://www.pcguide.com/ref/hdd/perf/qual/specCycles-c.h...
>
> Well, I'm reading that start/stop cycles are typically in the 30k to
> 50k range, and that's something I didn't know. I wasn't looking for the
> right keywords. One boot per day on a home PC would allow for 109 years
> at 40k cycles, which means other components must wear out faster than
> bearings! This is the info I needed.
>
> JT

Yes, one boot per day would be negligable, and wouldn't really be a
factor. But power saving modes could increase that a lot. If your HDD
powered down after 10 minutes of idle time (not unrealistic for a laptop
trying to save battery), it may cycle 40-50 times per day easily. So if
you divide 109 by 50, that's only a little over 2 years! Of course this
is an extreme case, and, as was noted in another post, notebook HDD's
are often engineered for more start/stop cycles. The thing to note is
that it *is* a design criteria. The other thing to hope is that as
desktop PC's become more power conserving, the HDD's had better be
designed for higher start/stop cycles.

Randy S.
Anonymous
a b G Storage
May 14, 2005 3:52:28 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

> Heat is a primary HDD killer. Still, spin-up induces more stress than
> normal operation, and many desktop HDDs are only rated for 50.000
> start/stop cycles. That is plenty for once a day. That is far to
> little for frequent spin-down. Since frequent spin-down is done in
> notebooks, notebook HDDs are usually rated for 500.000 start/stop
> cycles or more.

I hadn't seen those specs, but it sure as hell makes sense.

> If you operate a disk 24/7 without good cooling
> at, say, >70C, you might see the same fast death. In such circumstances
> _not_ running the disk permanently might actually extend its life
> significantly.

Well, yes, if you are running a piece of equipment in out-of-spec
conditions, I would expect minimizing the run time would extend its life
;-).

> There is one component that is put under very high stress at start-up,
> especially in a server with many disks: The Power Supply Unit. PSUs
> regularly fail on start-up and far less often during normal
> operation. That is one of several reasons why servers are usually
> running 24/7, even if they are not needed all the time. But take note
> that in Servers HDDs are usually cooled well.

Also, well designed servers will do a "staggered" start, i.e. they won't
start all of the hard drives at once, but at intervals, like 1 every 2
seconds. HDD startup takes a *lot* of juice, and if you have 5 or 6 or
more HDD's in a system you either have to *way* oversize your power
supply to handle the startup load, or more cheaply, stagger the start so
a smaller power supply can handle it. A staggered start can slow bootup
a *lot*, so it really discourages cold booting a server.

And a good admin will make sure that his drives aren't operating
over-temp, as you say.

Randy S.
Anonymous
a b G Storage
May 14, 2005 4:05:28 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Jack Tyler wrote:
> Rod Speed wrote:
>
>
>>>Would anyone claim that car wheel bearings get as much wear
>>>when you pull out of the driveway vs. a 500 mile nonstop trip?
>>
>>Completely different to hard drives.
>
>
> In principle it's the same, just with a lot more load on those wheel
> bearings. They take a lot of stress when you drive so I question that
> pulling out of the garage is significantly worse than a long trip on a
> hot day.

Maybe, though the load profiles are completely different as are the
design conditions. A hard drive operates with very little load, it only
needs to overcome frictional losses in the bearings and air resistance,
and maybe support a tiny bit of weight depending on the orientation of
the drive. A wheel bearing is supporting 1/4 the weight of your car at
all times (well, I suppose it varies, but it should *average* around
1/4), the load support is primary, overcoming frictional losses is a
distant second. Startup wear will still be greater than operating wear,
but I agree that it's doubtful that it's significant in that
application. But that doesn't mean it isn't significant in the HDD
application.

> Cold engine starts are different because oil has to be pulled
> up farther from the crankcase, though there's usually film left on the
> cylinder walls and crank bearings. Slick 50's claims of metal on metal
> are overhyped. But this is getting off topic.

So, as you note, different applications show varied significance of
startup wear. There's so little wear at operation on HDD's that startup
wear is bound to be significant. The film at startup on bearings
doesn't do you any good if there isn't enough force to form a pressure
wedge, however I throughly agree that products like Slick 50 overhype
such issues to sell stuff. Modern materials handle startup wear *much*
better than 30 years ago. Shoot, we have cars that need not much more
than an oil change for 100,000 miles now.

>>>Why does Windows have a "Turn off hard disks"
>>>feature in Power options if not to reduce bearing wear?
>>
>>To reduce power used, just like with monitors and motherboards.
>
>
> Other posters have claimed that power usage is nil but clearly it's
> not. My main angle on this was about saving energy. Multiply 5 watts by
> millions of computers and you've saved a lot of power. Do that with
> countless other gadgets and you've saved a lot more. People leave work
> monitors on all weekend (with goldfish tank displays) when they're
> gone. Too much trouble to push the off button or let the screen blank
> out? Diesel owners idle their engines way too much, etc..
>
> Anything that doesn't have to run 24/7 could be turned off instead of
> blaming it all on Kenneth Lay and the Arabs.

I think I mentioned that in a parenthetical comment before. While
anyone drive uses very little power, it can certainly argued that in
*aggregate* we could save quite a bit of power if it was conserved. Is
it cost effective? I can't answer that. I think we're probably headed
towards home systems where data is stored centrally and other units act
as smart (i.e. "thick") clients (think of storing all your
movies/music/pictures on a central device, then viewing them from in
your office, on your tv, in your kitchen, etc). I would say in that
situation, the data storage device would need to be on all the time, but
the other devices could aggessively power down when idle.

Randy S.
May 14, 2005 5:49:14 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

J. Clarke wrote:
> Jack Tyler wrote:
>
>> I have seen various comments like "we leave our servers running 24/7
>> because powering up a hard drive causes more wear than leaving it
>> running."
>
> This is the conventional wisdom. And it's not just disks. Thermal cycling
> used to be a serious problem with computers--that's why memory sockets have
> latches now. On an original IBM PC that had been running for a couple of
> years, sometimes the memory chips would walk completely out of the socket
> due to repeated thermal cycling.
>
>> I think it's mostly laziness and apathy about conserving
>> energy.
>
> Shutting down a large server farm is not something to be done lightly.
> Bringing it down and back up in an orderly fashion might take more than one
> night.
>
>> The TiVo forums discuss it a lot because a standard TiVo HD
>> runs all the time, buffering 30 minutes of whatever channel it's left
>> on.
>
> Yep, and they seem to last and last.
>
>> Do IT people who leave servers running 24/7 ever have much choice of
>> NOT leaving them on 24/7?
>
> Depends on the circumstances.
>
>> If not, how can they make scientific
>> comparisons of drive-bearing life?
>
> The viewpoint is generally based on experience with other mechanical
> devices.
>
>> As long as the head isn't moving,
>> bearing life seems to be the main concern.
>
> Even if the head is moving, bearing life is the main concern as far as
> _wear_ goes. The heads run on an air bearing--the wear is negligible.
>
> However disk seldom die of bearing failure--generally the failure is a crash
> or an electronics failure.
>
>> On a home PC left on all day
>> it's far less likely that the drive will be doing anything but spinning
>> at high RPM for no real reason.
>
> Maybe on _your_ system.
>
>> I've heard similar claims that the "shock" of turning on a light bulb
>> is worse than leaving it on all the time. Usually those comments came
>> as a way to excuse energy consumption after a debate on the merits of
>> waste. In reality, bulbs have a finite hours rating and will burn out
>> faster the longer they are left on, as long as they aren't flipped on
>> and off as torture. CFL bulbs (w/ballast) don't like to be switched on
>> and off quickly, but I can't imagine them burning out faster if you
>> only cycle on/off once in 10 minutes or so.
>
> You ever notice how light bulbs generally blow when you turn them on, not
> when they are just sitting there giving off light? It's called "thermal
> shock" and it's a real phenomenon.
>
>> Would anyone claim that car wheel bearings get as much wear when you
>> pull out of the driveway vs. a 500 mile nonstop trip? In that case, the
>> "spin up" would be when you first move the car after sitting. What
>> exactly causes the "big shock" when a hard drive spins up? The heat
>> generated from constant spinning would seem to far outweigh it. Why
>> does Windows have a "Turn off hard disks" feature in Power options if
>> not to reduce bearing wear?
>>
>> If anyone has thorough technical articles on hard drive wear, please
>> post. Specifically, what is so torturous about spinning up the drive,
>> and how can that brief cycle be quantified, damage-wise against
>> constant spinning with higher heat levels?
>
> The basic problem with any bearing is that at rest the mass supported by the
> bearing causes the rotating assembly to sink though the lubricant until it
> is touching something solid. When the device of whatever kind is started,
> there is a period before the lubricating film reestablishes itself in which
> there is metal-to-metal contact. Thus most of the wear occurs at startup.
> This is exacerbated by the fact that the lubricant is cold and thus does
> not flow well.
>
> The "heat generated from constant spinning", assuming that the drive is not
> being operated outside its rated temperature range, has negligible effect
> on the durability of the mechanical components--it would have more effect
> on the electronics but the electronic components are outside the capsule.

John... sounds like you know what you're talking about. So my question is: In my
Windows power scheme I have for years selected "Turn Off Hard Disks = after 3
hours". I have never noticed this actually happening. Sounds like you would
suggest turning this option off.
Possibly I don't notice the drive spinning down is that I seem to have fairly
constant network activity. I have a DU meter that monitors the network and it
pops up more often than every 3 hours. So maybe my 2 drives are not "turning
off".
Anonymous
a b G Storage
May 14, 2005 10:53:21 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

"Jack Tyler" <jctyler_67@yahoo.com> wrote:
> ....My main angle on this was about saving energy. Multiply 5 watts by
> millions of computers and you've saved a lot of power. Do that with
> countless other gadgets and you've saved a lot more. People leave work
> monitors on all weekend (with goldfish tank displays) when they're
> gone. Too much trouble to push the off button or let the screen blank
> out? Diesel owners idle their engines way too much, etc..
>
> Anything that doesn't have to run 24/7 could be turned off instead of
> blaming it all on Kenneth Lay and the Arabs.


What you and almost everyone else ignores is the energy used to
mine the raw materials and the energy to manufacure the components
and the energy to assemble those components into products. Add to
that the energy to get the workers to the manufacturing site, etc., and
it could very well be that more energy is used to make a product than
to operate it. So what you could have is a big energy WASTE if you
don't prolong the life of your products by minimizing the number of
power on/off cycles. In short, it's the overall cost in energy that counts,
not just the energy of operation.


Rick Lowen
Anonymous
a b G Storage
May 14, 2005 11:06:03 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

"zaw" <zaw@verizon.net> wrote:
> HDD are better when they're running and they're mounted Horizontally.
> That's where everything is perfect.

Reps at various HDD manufacturers say that orientation doesn't matter.


Rick Lowen
Anonymous
a b G Storage
May 15, 2005 12:14:04 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

"Richard Lowen" <LowensDen@HeissMail.com> wrote in message
news:bs-dnd7HCIrkNhvfRVn-pw@comcast.com...
>
> What you and almost everyone else ignores is the energy used to
> mine the raw materials and the energy to manufacure the components
> and the energy to assemble those components into products. Add to
> that the energy to get the workers to the manufacturing site, etc., and
> it could very well be that more energy is used to make a product than
> to operate it. So what you could have is a big energy WASTE if you
> don't prolong the life of your products by minimizing the number of
> power on/off cycles. In short, it's the overall cost in energy that
counts,
> not just the energy of operation.
>
Nonsense.

The energy to run a 100W computer for 5 years is 5*365*24*0.1 = 4380 kWh, or
$200-400. That exceeds the cost of entry level computers. Energy to
manufacture it is only a portion of that.
May 15, 2005 2:24:34 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

> Reps at various HDD manufacturers say that orientation doesn't matter.

Actually that is not true. They restrict hard drive position to
a few orientations.
Anonymous
a b G Storage
May 15, 2005 4:35:35 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Richard Lowen wrote:
> "zaw" <zaw@verizon.net> wrote:
>
>> HDD are better when they're running and they're mounted Horizontally.
>> That's where everything is perfect.
>
> Reps at various HDD manufacturers say that orientation doesn't matter.

I've heard that it is OK to run disks horizontal, vertical, or upside
down, but not diagonally. An older Dell PC I worked on yesterday has
one disk vertical at the front of the tower and the other disk upside
down under the floppy drive. Any orthogonal orientation is OK.
-Joe
Anonymous
a b G Storage
May 15, 2005 4:47:44 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

"Jack Tyler" <jctyler_67@yahoo.com> wrote in message news:1116082584.736454.303860@o13g2000cwo.googlegroups.com
> Howard wrote:
>
> > > If anyone has thorough technical articles on hard drive wear, please
> > > post. Specifically, what is so torturous about spinning up the drive,
> > > and how can that brief cycle be quantified, damage-wise against
> > > constant spinning with higher heat levels?
> >
> > You posted from google groups...so what did the archive say about the past
> > discussions on this topic?
>
> Lots of hearsay in past discussions. This thread has been a lot more
> informative.

Strange how more hearsay suddenly turns into information as soon as the
question is asked by poster as an originator rather than him being a lurker.

>
> JT
Anonymous
a b G Storage
May 15, 2005 4:53:37 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

"J. Clarke" <jclarke.usenet@snet.net.invalid> wrote in message news:D 63vqa01661@news4.newsguy.com
> Jack Tyler wrote:
>
> > I have seen various comments like "we leave our servers running 24/7
> > because powering up a hard drive causes more wear than leaving it running."
>
> This is the conventional wisdom. And it's not just disks. Thermal cycling
> used to be a serious problem with computers--that's why memory sockets have
> latches now. On an original IBM PC that had been running for a couple of
> years, sometimes the memory chips would walk completely out of the socket
> due to repeated thermal cycling.
>
> > I think it's mostly laziness and apathy about conserving energy.
>
> Shutting down a large server farm is not something to be done lightly.
> Bringing it down and back up in an orderly fashion might take more than
> one night.
>
> > The TiVo forums discuss it a lot because a standard TiVo HD runs
> > all the time, buffering 30 minutes of whatever channel it's left on.
>
> Yep, and they seem to last and last.
>
> > Do IT people who leave servers running 24/7 ever have much choice of
> > NOT leaving them on 24/7?
>
> Depends on the circumstances.
>
> > If not, how can they make scientific
> > comparisons of drive-bearing life?
>
> The viewpoint is generally based on ex-
> perience with other mechanical devices.
>
> > As long as the head isn't moving, bearing life seems to be the main concern.
>
> Even if the head is moving, bearing life is the main concern as far as
> _wear_ goes.

> The heads run on an air bearing--the wear is negligible.

> However disk seldom die of bearing failure--generally the failure

> is a crash

Which basically is a failure of 'air bearing'.
Sounds like "the wear is negligible" may not be so 'negligible' as expected.

> or an electronics failure.
>
> > On a home PC left on all day it's far less likely that the drive
> > will be doing anything but spinning at high RPM for no real reason.
>
> Maybe on _your_ system.
>
> > I've heard similar claims that the "shock" of turning on a light bulb
> > is worse than leaving it on all the time. Usually those comments came
> > as a way to excuse energy consumption after a debate on the merits of
> > waste. In reality, bulbs have a finite hours rating and will burn out
> > faster the longer they are left on, as long as they aren't flipped on
> > and off as torture. CFL bulbs (w/ballast) don't like to be switched on
> > and off quickly, but I can't imagine them burning out faster if you
> > only cycle on/off once in 10 minutes or so.
>
> You ever notice how light bulbs generally blow when you turn them on, not
> when they are just sitting there giving off light? It's called "thermal
> shock" and it's a real phenomenon.
>
> > Would anyone claim that car wheel bearings get as much wear when you
> > pull out of the driveway vs. a 500 mile nonstop trip? In that case, the
> > "spin up" would be when you first move the car after sitting. What
> > exactly causes the "big shock" when a hard drive spins up? The heat
> > generated from constant spinning would seem to far outweigh it. Why
> > does Windows have a "Turn off hard disks" feature in Power options if
> > not to reduce bearing wear?
> >
> > If anyone has thorough technical articles on hard drive wear, please
> > post. Specifically, what is so torturous about spinning up the drive,
> > and how can that brief cycle be quantified, damage-wise against
> > constant spinning with higher heat levels?
>
> The basic problem with any bearing is that at rest the mass supported by
> the bearing causes the rotating assembly to sink though the lubricant until
> it is touching something solid. When the device of whatever kind is started,
> there is a period before the lubricating film reestablishes itself in which
> there is metal-to-metal contact. Thus most of the wear occurs at startup.
> This is exacerbated by the fact that the lubricant is cold and thus does
> not flow well.
>
> The "heat generated from constant spinning", assuming that the drive is not
> being operated outside its rated temperature range, has negligible effect
> on the durability of the mechanical components--

> it would have more effect on the electronics but
> the electronic components are outside the capsule.

Except one very crucial pre-amp.
And the rest is bolted on close to the HDA with negligible to no airflow
between them.

>
> > Thanks.
> >
> > JT
Anonymous
a b G Storage
May 15, 2005 5:14:33 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

"Eric Gisin" <ericgisin@hotmail.com> wrote:..
> "Richard Lowen" <LowensDen@HeissMail.com> wrote:
>>
>> What you and almost everyone else ignores is the energy used to
>> mine the raw materials and the energy to manufacure the components
>> and the energy to assemble those components into products. Add to
>> that the energy to get the workers to the manufacturing site, etc., and
>> it could very well be that more energy is used to make a product than
>> to operate it. So what you could have is a big energy WASTE if you
>> don't prolong the life of your products by minimizing the number of
>> power on/off cycles. In short, it's the overall cost in energy that
>>counts, not just the energy of operation.
>>
> Nonsense.
>
> The energy to run a 100W computer for 5 years is 5*365*24*0.1 =
> 4380 kWh, or $200-400. That exceeds the cost of entry level computers.
> Energy to manufacture it is only a portion of that.


That's assuming you would run the computer 24/7. But if the question
is whether to turn it off every 1/4 hr for 1/4 of an hour AND turn it off for
12 hours (as most people do), the energy savings is only $25-$50, and
the life of the computer might be cut in half by the frequent power cycling.


Rick Lowen
Anonymous
a b G Storage
May 15, 2005 8:50:54 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Jack Tyler <jctyler_67@yahoo.com> wrote in message
news:1116082772.171080.158900@f14g2000cwb.googlegroups.com...
> Rod Speed wrote

>> There's a reason for the number of start stop
>> cycles specified in the hard drive datasheets.

> I think I need to find and read those datasheets.
> If you have any quick links, please post.

http://www.hgst.com/hdd/support/table3.htm
Generally in the Technical Library documentation link for each drive.
One specific example is
http://www.hitachigst.com/tech/techlib.nsf/techdocs/E8C...$file/d7k250P_sp.pdf
Anonymous
a b G Storage
May 15, 2005 9:00:21 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Jack Tyler <jctyler_67@yahoo.com> wrote in message
news:1116083555.966977.39450@g14g2000cwa.googlegroups.com...
> Rod Speed wrote:

>> The start stop cycles specified in the hard drive datasheets
>> are the most imporant numbers. They can be exceeded by
>> a startup every hour surprisingly quickly.

> http://www.pcguide.com/ref/hdd/perf/qual/specCycles-c.h...

> Well, I'm reading that start/stop cycles > are typically
> in the 30k to 50k range, and that's something I didn't
> know. I wasn't looking for the right keywords.

Yeah, thats the main problem.

> One boot per day on a home PC would
> allow for 109 years at 40k cycles,

But only a couple of years if you set it to power down on 30
mins of inactivity and it gets used at something like that rate,
say to poll for new email and dont turn it off overnight.

> which means other components must wear out faster than bearings!

Yes, bearing failure isnt seen much anymore with desktop hard drives.

Tho we havent been using fluid bearings
for all that long, so that may change too.

> This is the info I needed.
Anonymous
a b G Storage
May 15, 2005 9:14:52 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Jack Tyler <jctyler_67@yahoo.com> wrote in message
news:1116085334.241353.283510@g44g2000cwa.googlegroups.com...
> Rod Speed wrote

>>> Would anyone claim that car wheel bearings get as much wear
>>> when you pull out of the driveway vs. a 500 mile nonstop trip?

>> Completely different to hard drives.

> In principle it's the same,

Nope, nothing like it. The bearings are completely different,
you dont get anything like the spinup torque you get on a
hard drive platter with a car wheel, and the hard drive has
a single bearing on one end of the axle too.

> just with a lot more load on those wheel bearings.

Much bigger bearings.

> They take a lot of stress when you drive

The main stress on the bearings with car wheels
is when you drop into a pothole at speed etc.

> so I question that pulling out of the garage is
> significantly worse than a long trip on a hot day.

Nope.

> Cold engine starts are different because oil has to be pulled
> up farther from the crankcase, though there's usually film left
> on the cylinder walls and crank bearings. Slick 50's claims
> of metal on metal are overhyped. But this is getting off topic.

And completely different to a hard drive bearing anyway.

>>> Why does Windows have a "Turn off hard disks"
>>> feature in Power options if not to reduce bearing wear?

>> To reduce power used, just like with monitors and motherboards.

> Other posters have claimed that power usage is nil but clearly it's not.

Its in all the datasheets. 5W is pretty typical for a modern IDE drive.

> My main angle on this was about saving energy. Multiply 5 watts
> by millions of computers and you've saved a lot of power.

Still a fart in the bath in total power consumption.

> Do that with countless other gadgets and you've saved a lot more.

Still a fart in the bath in total power consumption.

> People leave work monitors on all weekend (with
> goldfish tank displays) when they're gone. Too much
> trouble to push the off button or let the screen blank out?

Hardly the end of civilisation as we know it any time soon.

> Diesel owners idle their engines way too much, etc..

> Anything that doesn't have to run 24/7 could be turned off

No thanks, I turn hardly anything off.

> instead of blaming it all on Kenneth Lay and the Arabs.

Wouldnt fix the problem even if they did
turn everything off that didnt need to be on.
Anonymous
a b G Storage
May 15, 2005 4:45:46 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

DanR wrote:

>
>
> J. Clarke wrote:
>> Jack Tyler wrote:
>>
>>> I have seen various comments like "we leave our servers running 24/7
>>> because powering up a hard drive causes more wear than leaving it
>>> running."
>>
>> This is the conventional wisdom. And it's not just disks. Thermal
>> cycling used to be a serious problem with computers--that's why memory
>> sockets have
>> latches now. On an original IBM PC that had been running for a couple of
>> years, sometimes the memory chips would walk completely out of the socket
>> due to repeated thermal cycling.
>>
>>> I think it's mostly laziness and apathy about conserving
>>> energy.
>>
>> Shutting down a large server farm is not something to be done lightly.
>> Bringing it down and back up in an orderly fashion might take more than
>> one night.
>>
>>> The TiVo forums discuss it a lot because a standard TiVo HD
>>> runs all the time, buffering 30 minutes of whatever channel it's left
>>> on.
>>
>> Yep, and they seem to last and last.
>>
>>> Do IT people who leave servers running 24/7 ever have much choice of
>>> NOT leaving them on 24/7?
>>
>> Depends on the circumstances.
>>
>>> If not, how can they make scientific
>>> comparisons of drive-bearing life?
>>
>> The viewpoint is generally based on experience with other mechanical
>> devices.
>>
>>> As long as the head isn't moving,
>>> bearing life seems to be the main concern.
>>
>> Even if the head is moving, bearing life is the main concern as far as
>> _wear_ goes. The heads run on an air bearing--the wear is negligible.
>>
>> However disk seldom die of bearing failure--generally the failure is a
>> crash or an electronics failure.
>>
>>> On a home PC left on all day
>>> it's far less likely that the drive will be doing anything but spinning
>>> at high RPM for no real reason.
>>
>> Maybe on _your_ system.
>>
>>> I've heard similar claims that the "shock" of turning on a light bulb
>>> is worse than leaving it on all the time. Usually those comments came
>>> as a way to excuse energy consumption after a debate on the merits of
>>> waste. In reality, bulbs have a finite hours rating and will burn out
>>> faster the longer they are left on, as long as they aren't flipped on
>>> and off as torture. CFL bulbs (w/ballast) don't like to be switched on
>>> and off quickly, but I can't imagine them burning out faster if you
>>> only cycle on/off once in 10 minutes or so.
>>
>> You ever notice how light bulbs generally blow when you turn them on, not
>> when they are just sitting there giving off light? It's called "thermal
>> shock" and it's a real phenomenon.
>>
>>> Would anyone claim that car wheel bearings get as much wear when you
>>> pull out of the driveway vs. a 500 mile nonstop trip? In that case, the
>>> "spin up" would be when you first move the car after sitting. What
>>> exactly causes the "big shock" when a hard drive spins up? The heat
>>> generated from constant spinning would seem to far outweigh it. Why
>>> does Windows have a "Turn off hard disks" feature in Power options if
>>> not to reduce bearing wear?
>>>
>>> If anyone has thorough technical articles on hard drive wear, please
>>> post. Specifically, what is so torturous about spinning up the drive,
>>> and how can that brief cycle be quantified, damage-wise against
>>> constant spinning with higher heat levels?
>>
>> The basic problem with any bearing is that at rest the mass supported by
>> the bearing causes the rotating assembly to sink though the lubricant
>> until it
>> is touching something solid. When the device of whatever kind is
>> started, there is a period before the lubricating film reestablishes
>> itself in which
>> there is metal-to-metal contact. Thus most of the wear occurs at
>> startup. This is exacerbated by the fact that the lubricant is cold and
>> thus does not flow well.
>>
>> The "heat generated from constant spinning", assuming that the drive is
>> not being operated outside its rated temperature range, has negligible
>> effect on the durability of the mechanical components--it would have more
>> effect on the electronics but the electronic components are outside the
>> capsule.
>
> John... sounds like you know what you're talking about. So my question is:
> In my Windows power scheme I have for years selected "Turn Off Hard Disks
> = after 3 hours". I have never noticed this actually happening. Sounds
> like you would suggest turning this option off.
> Possibly I don't notice the drive spinning down is that I seem to have
> fairly constant network activity. I have a DU meter that monitors the
> network and it pops up more often than every 3 hours. So maybe my 2 drives
> are not "turning off".

In practical terms it makes little difference. Disks are rated for a certain
large number of start-stop cycles--WD Raptors for example are rated for
20,000. If you're running a server it's unlikely that it's ever going to
be idle long enough for the disks to power down.

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)
Anonymous
a b G Storage
May 15, 2005 5:19:31 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Jack Tyler wrote:

> Rod Speed wrote:
>
>> > Would anyone claim that car wheel bearings get as much wear
>> > when you pull out of the driveway vs. a 500 mile nonstop trip?
>>
>> Completely different to hard drives.
>
> In principle it's the same, just with a lot more load on those wheel
> bearings. They take a lot of stress when you drive so I question that
> pulling out of the garage is significantly worse than a long trip on a
> hot day. Cold engine starts are different because oil has to be pulled
> up farther from the crankcase, though there's usually film left on the
> cylinder walls and crank bearings. Slick 50's claims of metal on metal
> are overhyped. But this is getting off topic.
>
>> > Why does Windows have a "Turn off hard disks"
>> > feature in Power options if not to reduce bearing wear?
>>
>> To reduce power used, just like with monitors and motherboards.
>
> Other posters have claimed that power usage is nil but clearly it's
> not. My main angle on this was about saving energy. Multiply 5 watts by
> millions of computers and you've saved a lot of power. Do that with
> countless other gadgets and you've saved a lot more. People leave work
> monitors on all weekend (with goldfish tank displays) when they're
> gone. Too much trouble to push the off button or let the screen blank
> out? Diesel owners idle their engines way too much, etc..
>
> Anything that doesn't have to run 24/7 could be turned off instead of
> blaming it all on Kenneth Lay and the Arabs.

You wanna see _waste_, go outside tonight and look up. And every single one
of those is blasting enough power into space in a single second to run all
of human civilization at its current level for about a million years.
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)
Anonymous
a b G Storage
May 15, 2005 6:14:33 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

>>Anything that doesn't have to run 24/7 could be turned off instead of
>>blaming it all on Kenneth Lay and the Arabs.
>
>
> You wanna see _waste_, go outside tonight and look up. And every single one
> of those is blasting enough power into space in a single second to run all
> of human civilization at its current level for about a million years.

This thread is taking some odd turns! I'm not sure it's relevent to
call the physics of stars waste. I would reserve that term for
excessive use of limited available resources.

Randy S.
Anonymous
a b G Storage
May 15, 2005 6:14:34 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

"Randy S." <rswittNO@SPAMgmail.com> wrote in message
news:D 683ia$te2$1@spnode25.nerdc.ufl.edu...
>
> >>Anything that doesn't have to run 24/7 could be turned off instead of
> >>blaming it all on Kenneth Lay and the Arabs.
> >
> > You wanna see _waste_, go outside tonight and look up. And every single
one
> > of those is blasting enough power into space in a single second to run
all
> > of human civilization at its current level for about a million years.
>
> This thread is taking some odd turns! I'm not sure it's relevent to
> call the physics of stars waste. I would reserve that term for
> excessive use of limited available resources.
>
Energy is not a limited resource. Our planet receives orders of magnitude
more than we need. Over 100e15 watts.
Anonymous
a b G Storage
May 15, 2005 8:18:48 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

In comp.sys.ibm.pc.hardware.storage Randy S. <rswittNO@spamgmail.com> wrote:
[...]
>> There is one component that is put under very high stress at start-up,
>> especially in a server with many disks: The Power Supply Unit. PSUs
>> regularly fail on start-up and far less often during normal
>> operation. That is one of several reasons why servers are usually
>> running 24/7, even if they are not needed all the time. But take note
>> that in Servers HDDs are usually cooled well.

> Also, well designed servers will do a "staggered" start, i.e. they won't
> start all of the hard drives at once, but at intervals, like 1 every 2
> seconds. HDD startup takes a *lot* of juice, and if you have 5 or 6 or
> more HDD's in a system you either have to *way* oversize your power
> supply to handle the startup load, or more cheaply, stagger the start so
> a smaller power supply can handle it. A staggered start can slow bootup
> a *lot*, so it really discourages cold booting a server.

Indeed. That is possibly an other factor.

Personally in my PC servers I go for PSUs that can take the full
spin-up load of all disks at once. That has the advantage that during
normal operation the PSU is not under higher load, which should
increase its lifetime. The limit for this is somewhere around 10-15
disks, since PSUs with more than 550W are dificult to get.

Arno
Anonymous
a b G Storage
May 15, 2005 8:18:49 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

> Indeed. That is possibly an other factor.
>
> Personally in my PC servers I go for PSUs that can take the full
> spin-up load of all disks at once. That has the advantage that during
> normal operation the PSU is not under higher load, which should
> increase its lifetime. The limit for this is somewhere around 10-15
> disks, since PSUs with more than 550W are dificult to get.

Most client PC's don't have any need for staggered spin-up, so I'd
totally agree with you. It's only in good size servers with lots of
RAIDed drives that it's really an issue.

Randy S.
Anonymous
a b G Storage
May 15, 2005 10:39:26 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

"Rod Speed" <rod_speed@yahoo.com> wrote in message news:3en11fF3uk2bU1@individual.net
> Jack Tyler <jctyler_67@yahoo.com> wrote in message news:1116085334.241353.283510@g44g2000cwa.googlegroups.com...
> > Rod Speed wrote
>
> > > > Would anyone claim that car wheel bearings get as much wear
> > > > when you pull out of the driveway vs. a 500 mile nonstop trip?
>
> > > Completely different to hard drives.
>
> > In principle it's the same,
>
> Nope, nothing like it. The bearings are completely different,
> you dont get anything like the spinup torque you get on a
> hard drive platter with a car wheel, and the hard drive has

> a single bearing on one end of the axle too.

Nonsense.

[snip]
Anonymous
a b G Storage
May 15, 2005 11:29:40 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Randy S. wrote:

>
>>>Anything that doesn't have to run 24/7 could be turned off instead of
>>>blaming it all on Kenneth Lay and the Arabs.
>>
>>
>> You wanna see _waste_, go outside tonight and look up. And every single
>> one of those is blasting enough power into space in a single second to
>> run all of human civilization at its current level for about a million
>> years.
>
> This thread is taking some odd turns! I'm not sure it's relevent to
> call the physics of stars waste. I would reserve that term for
> excessive use of limited available resources.

All resources are limited. Eventually it's _all_ going to run out, every
single bit of it. If stars weren't burning it so fast it would last a lot
longer. The solution, if we can't turn the stars off, is to enjoy it while
it lasts, because anything that _we_ do to save is negligible.

>
> Randy S.

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)
Anonymous
a b G Storage
May 16, 2005 2:09:53 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

When a lightbulb's filament is cold, its resistance is a fraction of its
operation resistance, because for pure metals, resistance about linearly
changes with absolute temperature. This causes initial overcurrent which may
burn a weakest spot of the filament. When this happens, an arch may form in
the argone gas, this is why one of conducting wires also usually melts.

"J. Clarke" <jclarke.usenet@snet.net.invalid> wrote in message
news:D 63vqa01661@news4.newsguy.com...
>
> You ever notice how light bulbs generally blow when you turn them on, not
> when they are just sitting there giving off light? It's called "thermal
> shock" and it's a real phenomenon.
>
Anonymous
a b G Storage
May 16, 2005 2:09:54 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Alexander Grigoriev wrote:

> When a lightbulb's filament is cold, its resistance is a fraction of its
> operation resistance, because for pure metals, resistance about linearly
> changes with absolute temperature. This causes initial overcurrent which
> may burn a weakest spot of the filament. When this happens, an arch may
> form in the argone gas, this is why one of conducting wires also usually
> melts.

Have you ever noticed that sometimes you can fix a light bulb by giving it a
light tap so the filament ends touch? Sometimes they'll weld if you do
that and it will run a while longer.

> "J. Clarke" <jclarke.usenet@snet.net.invalid> wrote in message
> news:D 63vqa01661@news4.newsguy.com...
>>
>> You ever notice how light bulbs generally blow when you turn them on, not
>> when they are just sitting there giving off light? It's called "thermal
>> shock" and it's a real phenomenon.
>>

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)
Anonymous
a b G Storage
May 16, 2005 2:21:54 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Considering that the HDD's bearing must be very tight (probably with
sub-micron play), in what ways do you think such tightness affects the
bearing's operation during startup and in steady mode?

"Randy S." <rswittNO@SPAMgmail.com> wrote in message
news:D 625ta$18f6$1@spnode25.nerdc.ufl.edu...
>
> Careful, you're showing your inexperience. If you are really asking the
> question, don't draw incorrect conclusions from assuming an answer.
> Startup wear is large for four reasons:
>
Anonymous
a b G Storage
May 16, 2005 2:21:55 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Alexander Grigoriev wrote:
> Considering that the HDD's bearing must be very tight (probably with
> sub-micron play), in what ways do you think such tightness affects the
> bearing's operation during startup and in steady mode?
>

I was being very general. Fit tolerences had large effects in bearings
that I used to design because often the inner race, outer race, and
bearing elements were all manufactured from different alloys (usually
titanium alloys, steel alloys and sometimes nickel or aluminum alloys).
The thermal coefficient (alpha) of these materials varied enough that
fit tolerences would change significantly as temperature changed.
You're correct that the fits are fairly tight (though *far* from
sub-micron, I think you're thinking of the bearing and race finishes,
which must be that close. Submicron fits wouldn't allow room for
lubrication movement, or even movement at all!), which *exacerbates*
thermal effects.

With HDD bearings, the inner and outer races are almost certainly the
same material, so thermal changes wouldn't change their fits, though the
bearing elements probably have some variation. Also, I was typically
working with thermal changes of 500 deg. F and up, HDD's only see a
delta of 100 degrees or so, so that would make it less significant.

Randy S.
Anonymous
a b G Storage
May 16, 2005 2:22:32 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

FWIW, the startup current causes a lot of stress in the drive
electronics too, especially the power circuitry and motor drivers. I
remember electrolytic caps blowing when you power cycled certain drives
too often. That may be less of an issue today than in the good old days
of many-platter 8" and 5.25" drives, but the electronics got smaller
too so it definitely gets stressed. Also, unless you have ramp loading
(which has its own set of issues), the heads get thermally stressed
through friction, in addition to the mechanical stress.
I leave my drives on 24*7.
Anonymous
a b G Storage
May 16, 2005 4:55:59 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

(Jason) wrote in alt.video.ptv.tivo:
> I hope they never put in such an option, because there have been
> plenty of times that 30 minute buffer has been astoundingly
> useful. For example, a few days ago when that 2-seater cessna
> flew over washington d.c. I walked into the room and saw people
> running down the street. 'What the hell?', I think; and rewinding
> 10 minutes gives the story.

That's why I want TiVo for real life. I could have seen it live if I would
have been able to back up 30 minutes and go outside.

--
Jeff Rife | "You keep using that word. I do not think it
| means what you think it means."
|
| -- Inigo Montoya, "The Princess Bride"
May 16, 2005 10:14:51 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

"Randy S." <rswittNO@SPAMgmail.com> wrote in news:D 6ajh0$u82$1
@spnode25.nerdc.ufl.edu:

> Well, I like the live buffer too, plus, as I think we've already reached
> a consensus on, the significance of full time operation of the HDD in a
> Tivo is probably close to nil.

I don't know if I would say that. The 'it's wasting energy!' people would
(and will...most likely within a week at the rate they have been going
lately) say it is a very high significance. They keep desperately reaching
for some other, more valid excuse though, and try to say you are doing no
harm by turning the device off. As we've all seen (many many times over
now, it surely is getting old) this not only keeps you from using the
device as it is intended, you ARE, in fact, doing harm.

Someday, they'll get a clue that it's not a 'waste' when I'm using the
energy IN THE EXACT WAY I WANT TO.

Ok, no they won't, but I can dream.

--
Minister of All Things Digital & Electronic, and Holder of Past Knowledge
stile99@email.com. Cabal# 24601-fnord | Sleep is irrelevant.
I speak for no one but myself, and |Caffeine will be assimilated.
no one else speaks for me. O- | Decaf is futile.
Anonymous
a b G Storage
May 16, 2005 10:14:52 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage,alt.video.ptv.tivo (More info?)

Howard wrote:
> "Randy S." <rswittNO@SPAMgmail.com> wrote in news:D 6ajh0$u82$1
> @spnode25.nerdc.ufl.edu:
>
>
>>Well, I like the live buffer too, plus, as I think we've already reached
>>a consensus on, the significance of full time operation of the HDD in a
>>Tivo is probably close to nil.
>
>
> I don't know if I would say that. The 'it's wasting energy!' people would
> (and will...most likely within a week at the rate they have been going
> lately) say it is a very high significance. They keep desperately reaching
> for some other, more valid excuse though, and try to say you are doing no
> harm by turning the device off. As we've all seen (many many times over
> now, it surely is getting old) this not only keeps you from using the
> device as it is intended, you ARE, in fact, doing harm.

Sorry, you're right, I meant to say that it as little significance to
the *reliability* of the device. Power savings are a different matter.
I wasn't precise enough ;-)

Randy S.
!