Typical mains power for mid-range PC?

Phat Bytestard wrote
Rod Speed wrote
Phat Bytestard wrote
Rod Speed wrote
kony wrote
Rod Speed wrote
Jon D wrote

If I have a hard drive which has a protective sheet of metal
on one side and the circuit board on the other side then
which of these two side should get the most cooling?

Varys with the drive design. The only real way to answer that
question is to try it both ways and monitor the drive SMART temp.

NO, it does not vary per drive design,

Fraid it does. Most obviously with the older Barras which
have a metal plate and rubber mat over the logic card etc.

or rather, all drive designs are putting the board
on the bottom, and a thin cover on the top,

Plenty of top covers arent thin.

thus need more cooling on the bottom
circuit board than (if any on) the top cover.

Not a ****ing clue, as always. Plenty of drives still get
rid of quite a bit of heat thru the metal body of the drive.

Drives exhibit heat on all their surfaces.

You quite sure you aint one of those rocket scientist drug crazed children ?

The emissivity of the surface determines the degree to which they radiate.

You quite sure you aint one of those rocket scientist drug crazed children ?

A shiny polished lid has a relatively low emissivity,
and yes, surface finish does matter.

You quite sure you aint one of those rocket scientist drug crazed children ?

That is why chips have matte finishes.

Pathetic, really.

I have drive mounts that do not have conduction paths for heat
through them. The drives are cooled completely by air currents.

Irrelevant to whether some drives get rid of quite a
bit of heat by conduction to the metal drive bay stack.

Totally relevant,

Nope, your drives have always been, and
always will be, completely and utterly irrelevant.

You in spades.

A rubber isolated drive conducts NO heat the "bay stack".

Pity that **** all are rubber insulated.

reams of your puerile **** that any 2 year old could leave for dead flushed where it
belongs

"Phat Bytestard" wrote

I use a 500 Watt PS. I'd like to think it runs cooler being barely
taxed than running a 250W drive (if you can even find one) taxed at
nearly its rated capacity.

Here's what silentpcreview.com has to say on p.3 of *Power Supply
Fundamentals & Recommendations*:


http://www.silentpcreview.com/article28-page3.html
Even so, Is Higher Power Better?

Without getting into technical details, the nature of a switching power
supply is that it delivers as much power as is demanded by the components.
This means that when installed in a PC whose components require 200W, a 400W
PSU and a 250W PSU will each deliver 200W. Does this mean the 400W is
coasting while the 250W is struggling? Not if they are both rated honestly
and if they have the same efficiency. If one has lower efficiency than the
other, then it will consume more AC to deliver the same power to the
components, and in the process, generate more heat within itself. As long as
there is adequate power, higher efficiency is the key to cooler, quieter PSU
operation.

The main benefit of higher power PSUs is when the airflow in the PSU is
deliberately set very low in order to minimize noise. This usually means the
PSU components will run hotter. If all other things are equal, a higher
rated PSU may be a better choice in such an application because its parts
are generally rated for higher current and heat than a lower rated model.


--
Ed Light

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Bring the Troops Home:
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On Sun, 30 Jul 2006 23:06:27 -0700, "Ed Light"
Gave us:


"Phat Bytestard" wrote

I use a 500 Watt PS. I'd like to think it runs cooler being barely
taxed than running a 250W drive (if you can even find one) taxed at
nearly its rated capacity.

Here's what silentpcreview.com has to say on p.3 of *Power Supply
Fundamentals & Recommendations*:


http://www.silentpcreview.com/article28-page3.html
Even so, Is Higher Power Better?

Without getting into technical details, the nature of a switching power
supply is that it delivers as much power as is demanded by the components.

I worked designing switchers for the last nine years. I don't
really need a primer.

This means that when installed in a PC whose components require 200W, a 400W
PSU and a 250W PSU will each deliver 200W.

That has never been dispute. If you read what I wrote, you would
see that the question was about efficiency. The 250 W supply pushing
200 W surely delivers only 200W as demanded by the load. The question
is, does it run hotter in doing so?

The 500W supply delivers only 200W to a 200W load as well, but may
be a lot more "comfortable" in doing so.

I can practically guarantee that the ripple on each supply rail will
be lower on the bigger supply.

Does this mean the 400W is
coasting while the 250W is struggling? Not if they are both rated honestly
and if they have the same efficiency.

Sure it does. As one approaches the rated capacity of a switcher,
the rated ripple voltages are going to be seen by the load (your PC).
In the case of PCs, that can be a bad thing.

If one has lower efficiency than the
other, then it will consume more AC to deliver the same power to the
components, and in the process, generate more heat within itself.

No ****. Basic math.

As long as
there is adequate power, higher efficiency is the key to cooler, quieter PSU
operation.

Who give a **** about fan noise? I am more concerned that the DC
being supplied to my PC is, in fact, DC, and not some electrically
noisy, high ripple psuedo-DC. With a cheap Chinese low wattage supply,
you can count on the latter.

The main benefit of higher power PSUs is when the airflow in the PSU is
deliberately set very low in order to minimize noise.

Again, mechanical noise means nothing to me.

This usually means the
PSU components will run hotter.

I doubt that my thermally monitored, high end PC supply runs hotter
than a cheap chinese OEM supply. Quite the opposite, in fact.

If all other things are equal, a higher
rated PSU may be a better choice in such an application because its parts
are generally rated for higher current and heat than a lower rated model.

They typically also supply a much quieter (ELECTRICALLY) DC source.

With a modern PC that has very low voltages utilized in it, this is
a MAJOR issue.

Remeber the old addage... You get what you pay for.

On 29 Jul 2006, Rod wrote:

kony wrote
Rod Speed wrote
Jon D wrote

If I have a hard drive which has a protective sheet of metal
on one side and the circuit board on the other side then
which of these two side should get the most cooling?

Varys with the drive design. The only real way to answer that
question is to try it both ways and monitor the drive SMART temp.

NO, it does not vary per drive design,

Fraid it does. Most obviously with the older Barras which
have a metal plate and rubber mat over the logic card etc.

or rather, all drive designs are putting the board
on the bottom, and a thin cover on the top,

Plenty of top covers arent thin.

[snip]


I have always wondered about the rubber sleeve which goes over almost
all of my old Seagate U6.

The drive can get quite warm and that rubber must make it worse.

Was the rubber there just for physical protection? Presumably for the
electronics (rather than the metal plate on the opposite side)?

Are there any disadvantages if I want to improve cooling by removing
this rubber sleeve?

On 31 Jul 2006, Phat
wrote:


Meaning a chip?

So, what's the upper limit to allow a HD to get to if running a hot
one in a less than greatly ventilated location?

I've been thinking of getting a newer one.

Thanks much!


External drive enclosures typically have no forced air cooling,
relying only on vent holes in the case. They even have small power
supplies in them.

I have seen drives so hot it is hard to keep a fingertip on them
for
an extended period operate for years without a problem. Even in
rough environments.

By the same token, I have seen a hot case cause a hard drive
failure.

Since Seagate was the primary company contracted by the mil boys
for
rough service applications, I have bought that brand for years, but
have also bought IBM (now Hitachi) and WD drives too.


Was Seagate producing the same drives for military apps as for
civilian or was Seagate producing a whole separate product line?


Have not had much luck with MaxTurd though.

But that is just me.

On Mon, 31 Jul 2006 08:15:32 +0100, Jon D Gave us:

On 29 Jul 2006, Rod wrote:

kony wrote
Rod Speed wrote
Jon D wrote

If I have a hard drive which has a protective sheet of metal
on one side and the circuit board on the other side then
which of these two side should get the most cooling?

Varys with the drive design. The only real way to answer that
question is to try it both ways and monitor the drive SMART temp.

NO, it does not vary per drive design,

Fraid it does. Most obviously with the older Barras which
have a metal plate and rubber mat over the logic card etc.

or rather, all drive designs are putting the board
on the bottom, and a thin cover on the top,

Plenty of top covers arent thin.

[snip]


I have always wondered about the rubber sleeve which goes over almost
all of my old Seagate U6.

The drive can get quite warm and that rubber must make it worse.

Not at all. The drive case, and the lid are never far off each other
temperature wise.

Even though the main heat source is the spindle motor, said heat
heats up the air in the platter box, and subsequently, the lid.

Both the case (platter box) as well as the lid give off a certain
degree of infra-red energy to the locale air. Having air move over
the drive carries of that hot air, and the process continues. This is
convection cooling.

Fins would be nice, but it was found that a "hot" drive is such a
typical scenario for the operating environ of the device that the
design should center around an elevated ambient norm. So smooth is
just fine, and dissipates plenty of heat. Having the lid and case as
thermally separate elements will make little or no difference.

Second to the heat generated by the spindle drive is the circuit
board that contains the electronics that drive the spindle motor and
the read/write MR head array. Most drives these days have all the
electronics on one PCB (not counting inside the drive on the head
arms), so included on said driver board would also be the digital I/O
electronics. I've had older drives that had two huge 5.25 x 6.5 inch
PCBs stacked on the bottom, and a 5.25 by 2 inch PCB on the back.
Electronics has come a long way.

Was the rubber there just for physical protection?

It is there for vibration isolation, which in turn yields a
mechanically quieter drive.

A drum (the musical device), when struck, will produce more noise
with the head attached to the resonating cavity better than one with
the head mounted on rubber gaskets. With a drum, the difference is
less, but the idea comes across.

A hard drive with a separate, non intimately contacting lid, will be
quieter when operating as the head seek noises will not couple to the
lid as well, which would produce a drum like effect.

Presumably for the
electronics (rather than the metal plate on the opposite side)?

Unsure what you mean, but The PCB assembly on the "bottom" of the
drive is typically elevated from the platter cavity/drive case, both
physically suspended, and thermally isolated... usually.

Nowadays, they are making PCBs that conduct heat right through the
PCB much better than in days of the past, so conductively cooled
designs may exist, but coupling to the drive case would be madness
since it operates at a higher temperature than the desired (and
achieved) operating temps of the driver/I/O PCB assemblies.

The air passing over a drive cools the entire drive, but is
primarily needed to cool the PCB assembly as it radiates to the air
less than the huge surface of the drive case, and has a number of
discreet components on it which need to have their generated heat
dissipated. They radiate to the air, and it gets carried off by the
air flow.

If the case temps these days were a problem, drive makers would be
making matte finish cases to help abate the heat, by radiating IR
better off the drive. Since they paint them up glossy, I'd say that
they have achieved the mean temperature they want the drive to run at,
at the mean external ambient they declare in their specs.
Typically 72 F.

Are there any disadvantages if I want to improve cooling by removing
this rubber sleeve?

You should not mess with your hard drive.

"Phat Bytestard" wrote

Who give a **** about fan noise? I am more concerned that the DC
being supplied to my PC is, in fact, DC, and not some electrically
noisy, high ripple psuedo-DC. With a cheap Chinese low wattage supply,
you can count on the latter.

The low wattage psu's they are talking about are active pfc, expensive, very
efficient, lots of amps on the 12v.

For instance, the Seasonic S12 330 has 22 amps on the 12v, if you count the
1 and 2 lines together, since they're coming off a single 12v supply.

It may be more efficient at typical pc wattages than a more powerful psu.
--
Ed Light

Smiley :-/
MS Smiley :-\

Send spam to the FTC at

Thanks, robots.

Bring the Troops Home:
http://bringthemhomenow.org

On Mon, 31 Jul 2006 08:24:42 +0100, Jon D Gave us:

Was Seagate producing the same drives for military apps as for
civilian or was Seagate producing a whole separate product line?


No. The drives they engineered were the state of the art, and Joe
Blow VAR got the same gear that the gov got. Makers didn't have a lot
of time to make multiple designs. One recount from that would be to
say that they MAY have had the drive maker use all mil parts, likely
quadrupling the cost of purchase, but I'd say that hard drives were
likely one of the first critical pieces of gear the mil boys bought
that didn't go through the rigors of mil standard manufacturing
processes. This would have been literally years before COTS ever hit
the scene.

A lot of technologies advanced as a result of hard drive technology.

The main differences between mil and consumer was in the design of
the carriages and other such equipment which these system components
were being integrated into.

For instance, at 70,000 feet in the air, the atmosphere is quite
thin, and pressurized cabins are NOT held at one atmosphere.

One either has to pass A LOT more air over a heat sink or make the
design such that conductive cooling methods can be utilized to carry
heat from operating systems.

Hard drives have been one of the most intensively "kept in the
design channel" as any device can be. They had to stay "state of the
art" at all times. Both mil as well as corporate IT admins tried to
stay right on the curl of that wave.

They have caused advances in chip design, motor design, motor
controller design, magneto-resistive head design. This is due to the
fact that it is truly the most important piece of equipment in ones
computer system. Then and now in the final analysis.

Today, however, we have storage subsystems that exist outside the
computer case, and that is actually safer for the drive lifespan,
albeit less safe from a data security POV.

I think the HD at LANL that was found behind the drinking fountain
was an internal 3.5 inch drive, so it required actual removal. from a
case. So much for my previous statement. :-]

On Mon, 31 Jul 2006 01:40:13 -0700, "Ed Light"
Gave us:

It may be more efficient at typical pc wattages than a more powerful psu.
--


That adds up to more than 250W for the 12V alone, and PC supplies
typically have a high current +5 Volt rail, not the 12V.

Also, a 250W supply has to supply all the voltages at the rated
power. Most cannot actually produce what they rate on each channel
(rail) with each fully loaded to their "rated capacity". The ripple
goes through the roof.

So, there is NO 250W supply that supplies 22 amps to the 12 Volt
rail. That is already beyond the output rating.

The reason the 500W supply is better is due to the fact that under
said lighter loading (250W), it will indeed also have a lower ripple
voltage on each of those rails. Lower still at the expected "average
PC" consumption level. I guarantee it, in fact. Unless it is some
**** copied design. A re-do of a switcher requires a full
re-characterization and tuning of the supply for peak efficiency and
clean stable operation. That means that any chinese knock off copy of
even a good design is not going to function the same without said
characterization and tuning routines.

Our LV switcher supplies were five times quieter than any competitor,
even OVER their rated spec for power, and I am referring to electrical
noise and clean operation.

Our standard HV supplies were ten times quieter than the nearest
competitor. Some were even far better than that. I had supplies
tuned to 0.000007% ripple, and 0.000033% regulation.

That equates to 10 mV ripple and 0.5V regulation on a 1500 Volt rail
out to 250W at 17kHz. Think of me on your next modern, hightech CAT
scan. All those detectors arrayed around you in that ring are fed the
cleanest voltages on the planet. This makes for the best CAT imagery
on the planet.

An X-ray exciter makes a cleaner flux if the excitation electron
stream is clean. This cleaner X-ray flux makes a higher contrast
ratio image. Think of me when you think about how safe your natural
gas lines are or your Nukes, or your airport baggage examining
stations.

Phat Bytestard wrote:
snip

Think of me when you think about how safe your natural
gas lines are or your Nukes, or your airport baggage examining
stations.

You would possibly prefer that I did not. My thoughts about airport
baggage scanners tend to be based on places like a Rome airport, and
many more, where the examiners were, if there at all, far to busy
chatting to each other than to actually look at the output of no doubt
excellent technology.

Hopefully the gas lines are better - but ISTR something about 3 Mile
Island and weld inspections?

I fear that the most common source of failure for any system, PCs
included, remains in the neural network controlling it..

--
Sue