kony wrote:
> On Thu, 13 Sep 2007 13:55:55 +1200, "~misfit~"
> <misfit61nz@hayoo.com.au> wrote:
>
>
> > An interesting fact for you Kony. A friend bought an end-of-line
> > Compaq just over a year ago. A Socket A Sempron. The first thing to
> > do with a machine like that, as you know, is to add some RAM. I
> > opened it up and noticed that the HDD was sitting right up under
> > the floppy, not in the airflow at all. There is a 90mm exhaust fan
> > and vents in the lower front of the case. I would have expected to
> > see the drive mounted down there.
> >
> > On closer inspection of the drive I saw that it was a 5,300rpm
> > drive! An 80GB 5,300rpm drive? I didn't know they made them. Every
> > drive I've bought in the last century, going back to a 20GB Maxtor,
> > has been 7,200rpm. (Discounting laptop drives of course.)
> >
> > Just thought it curious. The PC in question, even with extra RAM,
> > is slow as a wet week. It really needs that drive replacing.
> > However, that would require fabricating a new drive cage in
> > airflow. I might get around to it one day.
>
>
> I can't claim to have seen *all* Compaq models, but of those
> I've seen that weren't small form factor or under-monitor
> desktop type, they typically had a vertical screw-on
> carrier, and a couple slits in the bottom of the case (or
> holes tapped for screws).
>
> I'm wondering if the drive below the floppy was something
> the owner (or another person, later) did. What kind of case
> was it? It's unlikely I have all Compaq cases from that
> era, but I do have several.
It wasn't something the owner did, I actually unpacked the PC and installed
the RAM, burnt the recovery discs, removed Nortons, installed AVG, Adaware,
Spybot etc. and tweaked XP ("Optimise for best performace" "Windows
classic"....) to get the best out of it he could.
It's a mini-tower case, not SFF. Thinking back, perhaps the drive was in a
seperate drive cage. If so it would have only taken two drives (sandwiched
together) maximum, not much bigger than a cigarette packet, and it certainly
was nowhere near where the front vent was. (Much lower down the case.) As I
said, this was an end-of-line model and it was only around a year ago, maybe
18 months. Actually, almost exactly 18 months, just checked my calendar.
Sorry, I don't have the model number here. Also, I find that half the models
we get here in New Zealand are different to the "international" (read: US)
models.
On Sep 12, 10:01 pm, "~misfit~" <misfit6...@hayoo.com.au> wrote:
> Randy Brick MacKenna wrote:
> > On Sep 11, 9:27 pm, "~misfit~" <misfit6...@hayoo.com.au> wrote:
> > > Randy Brick MacKenna wrote:
> > > > I suppose I can live with this -- or upgrade to a better case --
> > > > but even so, I am still very surprised that a hard drive that is
> > > > marketed as "runningvery cool" can only achieve that distinction
> > > > when it is actively cooled.
>
> > > Seriously? They have motors in them that spin platters up to, and
> > > maintain at, at seven thousand two hundred revolutions per minute.
> > > Do you think that the heat produced from this motor (and the
> > > read/write heads actuator mechanism) is simply going to slip
> > > through the fabric of the universe into another dimension? They use
> > > around 20 watts. Imagine a 20 watt bulb in a closed box, (or a
> > > corner of a box without sufficient air movement). Howhot do you
> > > think it would get? (Ultimately, for the purposes of this analogy
> > > at least, all energy is given off as heat.) It doesn't matter much
> > > if a bulb getshot. Not so with a HDD though.
>
> > Yup, I agree now that active cooling is the norm for these
> > drives...thanks to everyone here for the education on that point.
>
> > But, are we sure the motor is the primary source of heat in these
> > drives? The amount of energy required to keep the platters spinning
> > at constant rotational velocity, once the target velocity has been
> > reached, should be minimal. Changes in speed (e.g. spin up or spin
> > down) take energy and produce heat -- but physics tells you that once
> > a platter is at speed, the amount of energy to keep it at that speed
> > is hardly anything. It's just got to overcome gravity and friction.
> > So, I'd bet that keeping a platter spinning at 7200 RPM consumes
> > barely measurably more energy than one at 5400 RPM.
>
> > I thought the main source of heat in these drives was the (ever
> > denser) packaging of the electronics within them...maybe I'm wrong and
> > it is the motor...but I can't picture it...
>
> Randy, forgot to mention in my other reply to you. If HDDs spinning at
> 5,300rpm and 7,200rpm used similar amounts of energy (and therefore gave off
> similar amounts of heat) why is it that (by far the majority of) laptop
> drives are still either 4,200rpm or 5,300rpm? Maybe you know something that
> laptop manufacturers don't? The difference in response times between 7,200
> and 5,300 drives is vey noticable. If there was a "barely measurable"
> difference in energy consumption surely they'd want their laptops to be
> significantly more responsive?
>
> Cheers,
> --
> TTFN.
>
> Shaun.
I didn't realize they were still offering 4200rpm drives in
laptops...Dell and Lenovo seem to be a mix of 5400 and 7200.
Anyway, here's why I think we don't see more 7200rpm drives in
laptops: it's due to the higher power consumption/heat generated by a
7200rpm drive. However, this has to do with spin-up energy, not
steady-state. The energy required to get a 7200rpm drive up to speed
is significantly higher than that of a 5400rpm drive. Since laptops
by default are running ACPI pretty aggressively (in battery mode),
they are going to be starting and stopping the HD a whole lot more
than a desktop. The energy hit at getting up to 7200rpm versus
5400rpm is too great, as well is the latency while waiting for the
platters to reach target speed.
Randy Brick MacKenna wrote:
> On Sep 12, 10:01 pm, "~misfit~" <misfit6...@hayoo.com.au> wrote:
> > Randy Brick MacKenna wrote:
> > > On Sep 11, 9:27 pm, "~misfit~" <misfit6...@hayoo.com.au> wrote:
> > > > Randy Brick MacKenna wrote:
> > > > > I suppose I can live with this -- or upgrade to a better case
> > > > > -- but even so, I am still very surprised that a hard drive
> > > > > that is marketed as "runningvery cool" can only achieve that
> > > > > distinction when it is actively cooled.
> >
> > > > Seriously? They have motors in them that spin platters up to,
> > > > and maintain at, at seven thousand two hundred revolutions per
> > > > minute. Do you think that the heat produced from this motor
> > > > (and the read/write heads actuator mechanism) is simply going
> > > > to slip through the fabric of the universe into another
> > > > dimension? They use around 20 watts. Imagine a 20 watt bulb in
> > > > a closed box, (or a corner of a box without sufficient air
> > > > movement). Howhot do you think it would get? (Ultimately, for
> > > > the purposes of this analogy at least, all energy is given off
> > > > as heat.) It doesn't matter much if a bulb getshot. Not so with
> > > > a HDD though.
> >
> > > Yup, I agree now that active cooling is the norm for these
> > > drives...thanks to everyone here for the education on that point.
> >
> > > But, are we sure the motor is the primary source of heat in these
> > > drives? The amount of energy required to keep the platters
> > > spinning at constant rotational velocity, once the target
> > > velocity has been reached, should be minimal. Changes in speed
> > > (e.g. spin up or spin down) take energy and produce heat -- but
> > > physics tells you that once a platter is at speed, the amount of
> > > energy to keep it at that speed is hardly anything. It's just
> > > got to overcome gravity and friction. So, I'd bet that keeping a
> > > platter spinning at 7200 RPM consumes barely measurably more
> > > energy than one at 5400 RPM.
> >
> > > I thought the main source of heat in these drives was the (ever
> > > denser) packaging of the electronics within them...maybe I'm
> > > wrong and it is the motor...but I can't picture it...
> >
> > Randy, forgot to mention in my other reply to you. If HDDs spinning
> > at 5,300rpm and 7,200rpm used similar amounts of energy (and
> > therefore gave off similar amounts of heat) why is it that (by far
> > the majority of) laptop drives are still either 4,200rpm or
> > 5,300rpm? Maybe you know something that laptop manufacturers don't?
> > The difference in response times between 7,200 and 5,300 drives is
> > very noticable. If there was a "barely measurable" difference in
> > energy consumption surely they'd want their laptops to be
> > significantly more responsive?
> >
> > Cheers,
> > --
> > TTFN.
> >
> > Shaun.
>
> I didn't realize they were still offering 4200rpm drives in
> laptops...Dell and Lenovo seem to be a mix of 5400 and 7200.
Yeah, look around at the lower ranges of laptops.
> Anyway, here's why I think we don't see more 7200rpm drives in
> laptops: it's due to the higher power consumption/heat generated by a
> 7200rpm drive. However, this has to do with spin-up energy, not
> steady-state.
Then why spin them up more than once per power-cycle?
> The energy required to get a 7200rpm drive up to speed
> is significantly higher than that of a 5400rpm drive. Since laptops
> by default are running ACPI pretty aggressively (in battery mode),
> they are going to be starting and stopping the HD a whole lot more
> than a desktop. The energy hit at getting up to 7200rpm versus
> 5400rpm is too great, as well is the latency while waiting for the
> platters to reach target speed.
>
> Now tell me how wrong I am ;-)
>
> -Randy
Sure, no problem. <g>
You say that it's nothing to do with steady-state. If that's the case then
why stop/start the drives at all? Surely, if the power involved in keeping a
drive at 7,200rpm is no big deal then you'd simply run it up to speed and
keep it there? Starting and stopping a drive sounds far more
energy-intensive than spinning it up and keeping it at speed. Unless keeping
a drive at 7,200rpm (steady-state) is more power-hungry than stopping and
starting a 5,300rpm drive.
If I hadn't had a few glasses <cough> of port, followed by a tumbler of
Johnnie Walker Black label on the rocks I'm sure this would sound a lot more
convincing. <g>
Why would you be spinning up and then allowing a drive to stop if it wasn't
saving energy compared to keeping it spinning?
--
TTFN.
Re: Caviar drive - running too hot? 
Linear Mode
