Has anybody ever stacked two CPU coolers?

Rene Lamontagne wrote:
On 2020-07-25 5:33 p.m., Paul wrote:
https://www.quietpc.com/tnn500af

That case sure has a lot of good engineering put into it, I can see why
it has casters, it weighs about 70 lbs, I looked around a bit but
couldn't find a price on it yet.
It will be great for audio and such purposes.

I'm not in need of one because one of the perks of old age is a much
reduced sound perception (what did you say). :-)

Rene

That case was $1000, and was a popular item in audio
recording studios. It doesn't have the power handling
for gamers. Without a lot of effort, you need at least
one fan in it again, if you put large thermal loads
in it.

That one probably isn't for sale any more.

They made two models, the second being an attempt
to cost reduce the first.

Even if there were patents, I don't think the market
is large enough for anyone bothering to steal that
market. You can't make heatpipes for nothing, so you're
unlikely to see a $50 computer case built like that.
And unless you can bring down the price a lot,
the project isn't going anywhere.

If someone brought out one for $600, they wouldn't
sell a lot. They have to get the price down to $55
to sell it now.

Paul

"Rene Lamontagne" wrote in message
...
On 2020-07-25 5:33 p.m., Paul wrote:
Commander Kinsey wrote:
Has anybody ever stacked two CPU coolers? First one fitted normally,
then the second welded on top of it. Theoretically, you have twice the
cooling, if it conducts through the first fast enough. I'm referring to
the type with the fan on the side.

Call me, when your solution uses heatpipes.

Look at the Zalman completely-passive cooling
computer case, if you want to see how to do it.
It moves heat from one place to another with
heatpipes. The exterior of the case is the
final destination.

https://www.quietpc.com/tnn500af



That case sure has a lot of good engineering put into it, I can see why it
has casters, it weighs about 70 lbs, I looked around a bit but couldn't
find a price on it yet.
It will be great for audio and such purposes.

I'm not in need of one because one of the perks of old age is a much
reduced sound perception (what did you say). :-)


FYI - top of the page.

TNN 500AF Totally No Noise Computer Case
Discontinued

--
Regards
wasbit

Commander Kinsey wrote:
On Sat, 25 Jul 2020 23:33:54 +0100, Paul wrote:

Commander Kinsey wrote:
Has anybody ever stacked two CPU coolers? First one fitted normally,
then the second welded on top of it. Theoretically, you have twice the
cooling, if it conducts through the first fast enough. I'm referring to
the type with the fan on the side.

Call me, when your solution uses heatpipes.

It does. Two coolers, each with their own 4 heatpipes.

Look at the Zalman completely-passive cooling
computer case, if you want to see how to do it.
It moves heat from one place to another with
heatpipes. The exterior of the case is the
final destination.

https://www.quietpc.com/tnn500af

No no and no. I once bought a "silent power supply" that threw it's heat
out the back with a sticky out heatsink. It went bang after a few months.

Only with heatpipes, can you move heat from
the origin, to the second heatsink, and expect
to get improved performance.

And both the heatsinks have heatpipes running through them.

That's why heatpipes are used, between baseplate
and top-of-fins, so that an excessively-long fin
does some work for you.

It's also why a 50mm tall 40mm square heatsink,
is no more effective than a 25mm tall 40mm square heatsink.
Those are used on chipsets. The upper portion of the
taller unit, has insufficient thermal conduction
for the top of the fins to remove heat. It means
making fins longer and longer (without heatpipes),
is asymptotic. At some point, a longer fin adds
nothing to the solution.

I can't believe that, metal is a very good conductor.

But none is superconducting so there'll always be efficiency losses over
distance. Not all metals are the same which is why sinks are a mix of
copper and aluminium and not made of steel. Any joins also reduce
efficiency. It all adds up to a bad idea.

The top of tall ones can still be hot to touch.

Once you lace the parts together with heatpipes,
then we'll talk. There's a limit to how many
heatpipes can be fitted, and some thought has to be
put into where the heatpipe is moving the heat.

I would have 4 heatpipes running through the bottom half, and 4 through
the top half. There would only be a short interface of normal metal to join the two.

You place the heatpipe at the source, as only if
the heatpipe is in intimate contact, does its 1000x
better performance, work. Just ramming a pipe into
a block with 3 inches of aluminum between the
baseplate and the pipe, that would be useless too.
As the 3 inches of aluminum is a huge thermal
resistance, and the zero resistance of the heatpipe
on top cannot then help. The heatpipes always start
in the baseplate, touching the CPU.

Doesn't have to. The top of the existing heatsink is too hot to touch.
So the heatpipes on the new heatsink will take heat away from there.

Compare it to the temperature of the CPU. It's probably already lost 30-40
°C. Another sink would lose that again.

Anyway, if you don't believe any of this. Why not just do it and let us
know how you get on?

On 26/07/2020 00.47, Commander Kinsey wrote:
On Sat, 25 Jul 2020 23:33:54 +0100, Paul wrote:

Commander Kinsey wrote:
Has anybody ever stacked two CPU coolers? First one fitted normally,
then the second welded on top of it. Theoretically, you have twice the
cooling, if it conducts through the first fast enough. I'm referring to
the type with the fan on the side.

Call me, when your solution uses heatpipes.

It does.* Two coolers, each with their own 4 heatpipes.

Look at the Zalman completely-passive cooling
computer case, if you want to see how to do it.
It moves heat from one place to another with
heatpipes. The exterior of the case is the
final destination.

https://www.quietpc.com/tnn500af

No no and no.* I once bought a "silent power supply" that threw it's
heat out the back with a sticky out heatsink.* It went bang after a few
months.

Only with heatpipes, can you move heat from
the origin, to the second heatsink, and expect
to get improved performance.

And both the heatsinks have heatpipes running through them.

That's why heatpipes are used, between baseplate
and top-of-fins, so that an excessively-long fin
does some work for you.

It's also why a 50mm tall 40mm square heatsink,
is no more effective than a 25mm tall 40mm square heatsink.
Those are used on chipsets. The upper portion of the
taller unit, has insufficient thermal conduction
for the top of the fins to remove heat. It means
making fins longer and longer (without heatpipes),
is asymptotic. At some point, a longer fin adds
nothing to the solution.

I can't believe that, metal is a very good conductor.* The top of tall
ones can still be hot to touch.

Metal is not as good a heat conductor as heat pipes, or liquid cooling.



Once you lace the parts together with heatpipes,
then we'll talk. There's a limit to how many
heatpipes can be fitted, and some thought has to be
put into where the heatpipe is moving the heat.

I would have 4 heatpipes running through the bottom half, and 4 through
the top half.* There would only be a short interface of normal metal to
join the two.

You place the heatpipe at the source, as only if
the heatpipe is in intimate contact, does its 1000x
better performance, work. Just ramming a pipe into
a block with 3 inches of aluminum between the
baseplate and the pipe, that would be useless too.
As the 3 inches of aluminum is a huge thermal
resistance, and the zero resistance of the heatpipe
on top cannot then help. The heatpipes always start
in the baseplate, touching the CPU.

Doesn't have to.* The top of the existing heatsink is too hot to touch.
So the heatpipes on the new heatsink will take heat away from there.

Then what you need is a better heatsink. Or maybe not.

Post a photo or drawing.


This is why we buy a larger heatsink, like a Noctua.
Instead of impishly welding stuff together, the
heatpipes on the properly-designed unit, have been
selected for the perfect location to get the
best effect. While the unit may be designed with
two fans, it works quite well with only the
central fan fitted.

Heatpipes have non-linear behavior. If you pump too
much heat into them, the liquid-vapor phase transfer
stops because all the materials remain in the vapor
phase. The manufacturer will usually suggest a max
power as a practical limit (before the pipes saturate
and the degree-of-cooling ends up actually reduced).
If you put six pipes in parallel, as soon as one
pipe saturates, the other five carry the load and
then they drop in quick succession.

What temperature should the CPU be for optimal heatpipe cooling?

In theory, a heatsink is designed to work best with a certain cpu.

--
Cheers, Carlos.

On Sat, 25 Jul 2020 23:01:26 +0100, Wolffan wrote:

On 25 Jul 2020, Commander Kinsey wrote
(in article op.0obycr1swdg98l@glass):

On Sat, 25 Jul 2020 21:52:31 +0100, wrote:

On 25 Jul 2020, Commander Kinsey wrote
(in article op.0oboc2f2wdg98l@glass):

Has anybody ever stacked two CPU coolers? First one fitted normally, then
the
second welded on top of it. Theoretically, you have twice the cooling,

no, you won’t.

if it
conducts through the first fast enough. I'm referring to the type with the
fan on the side.

there are numerous sites out there which cover this; I first encountered
this
idea in 2001. (Yes, 2001. Not a typo. And it wasn’t a new idea then, it
was
just new to me.) It turns out that doubling the fans gives from -5%
(that’s
_negative_ five percent, it can make things worse) to +65% airflow,
depending
on numerous factors. (Size of fan, are the fans spinning in the same
direction or in opposite directions, fan speed, how fans are placed relative
to the heat exchanger, space inside the computer’s case, location of CPU
relative to sides of computer case, location of other items including hard
drives, RAM, power supplies, video and/or sound cards, type of case
especially with respect to vents, internal cabling, more.) However, airflow
and cooling do not necessarily scale together. Merely increasing the airflow
does not necessarily do much for the cooling, for that you need heat
exchangers attached to the CPU, heat exchangers attached to another heat
exchanger don’t do much, and airflow is a square effect while heat
exchangers are a cube effect. Airflow maxed out at around +65% for two fans;
cooling maxed out at about +45%. And it took considerable effort to get that
+45%, most systems were considerably lower than that. There would be a
_reason_ why liquid cooling is popular. It’s actually simpler and easier
to
do. Most modern CPUs generate a whole lot less heat than CPUs dating from
2001 did, so a good way to get a cooler-running system is toi use a newer
CPU. And to stay way from the heat-producing monsters, notably IBM Power
CPUs, which have improved no end since then but which are still devices to
convert electricity into heat, something anyone who ever went near a G5- or
a
G4- powered Mac could tell you. (One G4 Mac was called the Windtunnel
because
of the noise level from the fans to keep the CPU cool; one G5 Mac shipped
with liquid cooling because Apple didn’t want to ship Windtunnel Mk 2...)
IBM is up to Power 8 or 9 or some such now, where G5s were Power 5s, and
they’re much better behaved, but still...

Doubling the size of the heatsink (and also the number of fans, which won't
blow towards each other) must make a considerable difference. It will be
twice the cooling effect, minus the lack of conduction through the first
heatsink, which I assume will conduct well, being metal and all that.

You’re not going to get anywhere close to double the cooling. Instead of
kludging together two fans, just buy one of the properly-designed dual fan
units out there. (which don’t get twice the cooling of similar single-fan
designs from the same company, pros can’t get double the cooling either.
Not even close. Look at the specs for yourself.) Or, if you’re serious
about cooling, use liquid cooling.

What you _will_ get with a dual-fan system is twice the noise. Especially if
you use small-diameter fans.

Dual fan is pointless. Each fan is designed to push x amount of air, adding another one in it's path won't speed that air up. You only get better airflow from faster fans, or fans in parallel. Series is stupid.

Anyway I fixed it, by changing the fan, I'd forgotten that some fans are really crap - they can be anything from 1100rpm to 4000rpm. I happened to have a few 3000rpm fans sitting about, so I replaced what looks like about 1100rpm with 3000rpm, and lost 20C of temperature. What's odd is I used to have one CPU at 65C and one at 75C (with identical coolers), and now the 75C has dropped to 55C. I guess the physical position meant cooler air for one of them.

On Sun, 26 Jul 2020 00:41:40 +0100, Wolffan wrote:

On 25 Jul 2020, Commander Kinsey wrote
(in article op.0ob3ngs7wdg98l@glass):

On Sat, 25 Jul 2020 23:08:09 +0100, wrote:

On 25/07/2020 23:01, Wolffan wrote:
On 25 Jul 2020, Commander Kinsey wrote
(in article op.0obycr1swdg98l@glass):

On Sat, 25 Jul 2020 21:52:31 +0100, wrote:

On 25 Jul 2020, Commander Kinsey wrote
(in article op.0oboc2f2wdg98l@glass):

Has anybody ever stacked two CPU coolers? First one fitted normally,
then
the
second welded on top of it. Theoretically, you have twice the cooling,

no, you won’t.

if it
conducts through the first fast enough. I'm referring to the type with
the
fan on the side.

there are numerous sites out there which cover this; I first encountered
this
idea in 2001. (Yes, 2001. Not a typo. And it wasn’t a new idea then, it
was
just new to me.) It turns out that doubling the fans gives from -5%
(that’s
_negative_ five percent, it can make things worse) to +65% airflow,
depending
on numerous factors. (Size of fan, are the fans spinning in the same
direction or in opposite directions, fan speed, how fans are placed
relative
to the heat exchanger, space inside the computer’s case, location of
CPU
relative to sides of computer case, location of other items including
hard
drives, RAM, power supplies, video and/or sound cards, type of case
especially with respect to vents, internal cabling, more.) However,
airflow
and cooling do not necessarily scale together. Merely increasing the
airflow
does not necessarily do much for the cooling, for that you need heat
exchangers attached to the CPU, heat exchangers attached to another heat
exchanger don’t do much, and airflow is a square effect while heat
exchangers are a cube effect. Airflow maxed out at around +65% for two
fans;
cooling maxed out at about +45%. And it took considerable effort to get
that
+45%, most systems were considerably lower than that. There would be a
_reason_ why liquid cooling is popular. It’s actually simpler and
easier
to
do. Most modern CPUs generate a whole lot less heat than CPUs dating from
2001 did, so a good way to get a cooler-running system is toi use a newer
CPU. And to stay way from the heat-producing monsters, notably IBM Power
CPUs, which have improved no end since then but which are still devices
to
convert electricity into heat, something anyone who ever went near a G5-
or
a
G4- powered Mac could tell you. (One G4 Mac was called the Windtunnel
because
of the noise level from the fans to keep the CPU cool; one G5 Mac shipped
with liquid cooling because Apple didn’t want to ship Windtunnel Mk
2...)
IBM is up to Power 8 or 9 or some such now, where G5s were Power 5s, and
they’re much better behaved, but still...

Doubling the size of the heatsink (and also the number of fans, which
won't
blow towards each other) must make a considerable difference. It will be
twice the cooling effect, minus the lack of conduction through the first
heatsink, which I assume will conduct well, being metal and all that.

You’re not going to get anywhere close to double the cooling. Instead of
kludging together two fans, just buy one of the properly-designed dual fan
units out there. (which don’t get twice the cooling of similar single-fan
designs from the same company, pros can’t get double the cooling either.
Not even close. Look at the specs for yourself.) Or, if you’re serious
about cooling, use liquid cooling.

What you _will_ get with a dual-fan system is twice the noise. Especially
if
you use small-diameter fans.

Why are you talking down to a Computer Science graduate, Wolffan?

Apple *FAN* BOISE have no experience of such matters. :-P

You are way out of your league here.

Are you not an Apple fan (can't call you a boy at your age) yourself?

he’s an idiot.

Apart from believing in god and using Apples, no he isn't. He's just down the road from me (well 500 miles).

On Sun, 26 Jul 2020 02:45:51 +0100, Paul wrote:

Rene Lamontagne wrote:
On 2020-07-25 5:33 p.m., Paul wrote:
https://www.quietpc.com/tnn500af

That case sure has a lot of good engineering put into it, I can see why
it has casters, it weighs about 70 lbs, I looked around a bit but
couldn't find a price on it yet.
It will be great for audio and such purposes.

I'm not in need of one because one of the perks of old age is a much
reduced sound perception (what did you say). :-)

Rene

That case was $1000, and was a popular item in audio
recording studios.

Just had a quick look, how on earth do you affix the coolers to the CPU, GPU, etc? Heatpipes aren't flexible. And even worse if the CPU or GPU isn't in the place the case designer thought it would be.

On Sun, 26 Jul 2020 12:27:38 +0100, Carlos E.R. wrote:

On 26/07/2020 00.47, Commander Kinsey wrote:
On Sat, 25 Jul 2020 23:33:54 +0100, Paul wrote:

Commander Kinsey wrote:
Has anybody ever stacked two CPU coolers? First one fitted normally,
then the second welded on top of it. Theoretically, you have twice the
cooling, if it conducts through the first fast enough. I'm referring to
the type with the fan on the side.

Call me, when your solution uses heatpipes.

It does. Two coolers, each with their own 4 heatpipes.

Look at the Zalman completely-passive cooling
computer case, if you want to see how to do it.
It moves heat from one place to another with
heatpipes. The exterior of the case is the
final destination.

https://www.quietpc.com/tnn500af

No no and no. I once bought a "silent power supply" that threw it's
heat out the back with a sticky out heatsink. It went bang after a few
months.

Only with heatpipes, can you move heat from
the origin, to the second heatsink, and expect
to get improved performance.

And both the heatsinks have heatpipes running through them.

That's why heatpipes are used, between baseplate
and top-of-fins, so that an excessively-long fin
does some work for you.

It's also why a 50mm tall 40mm square heatsink,
is no more effective than a 25mm tall 40mm square heatsink.
Those are used on chipsets. The upper portion of the
taller unit, has insufficient thermal conduction
for the top of the fins to remove heat. It means
making fins longer and longer (without heatpipes),
is asymptotic. At some point, a longer fin adds
nothing to the solution.

I can't believe that, metal is a very good conductor. The top of tall
ones can still be hot to touch.

Metal is not as good a heat conductor as heat pipes, or liquid cooling.

But it's a very short distance to travel between the heatpipes of the bottom one and the heatpipes of the top one.

Once you lace the parts together with heatpipes,
then we'll talk. There's a limit to how many
heatpipes can be fitted, and some thought has to be
put into where the heatpipe is moving the heat.

I would have 4 heatpipes running through the bottom half, and 4 through
the top half. There would only be a short interface of normal metal to
join the two.

You place the heatpipe at the source, as only if
the heatpipe is in intimate contact, does its 1000x
better performance, work. Just ramming a pipe into
a block with 3 inches of aluminum between the
baseplate and the pipe, that would be useless too.
As the 3 inches of aluminum is a huge thermal
resistance, and the zero resistance of the heatpipe
on top cannot then help. The heatpipes always start
in the baseplate, touching the CPU.

Doesn't have to. The top of the existing heatsink is too hot to touch.
So the heatpipes on the new heatsink will take heat away from there.

Then what you need is a better heatsink. Or maybe not.

No, it seems I needed a better fan. It's a cheap heatsink/fan I got (I bought 4 to service two dual Xeon machines which I built from parts, and I had no spare heatsinks that would fit the unusual socket size). Strangely only one of the 4 CPUs seems to get too hot. They're in a similar place physically - open motherboard, no case, on a bookshelf with 4 120mm high speed fans blowing air across the shelf front to back. Turns out the fan on the heatsink was about 1000RPM, I found a 3000rpm fan in a box and swapped it in. 20C cooler!

Post a photo or drawing.

This is why we buy a larger heatsink, like a Noctua.
Instead of impishly welding stuff together, the
heatpipes on the properly-designed unit, have been
selected for the perfect location to get the
best effect. While the unit may be designed with
two fans, it works quite well with only the
central fan fitted.

Heatpipes have non-linear behavior. If you pump too
much heat into them, the liquid-vapor phase transfer
stops because all the materials remain in the vapor
phase. The manufacturer will usually suggest a max
power as a practical limit (before the pipes saturate
and the degree-of-cooling ends up actually reduced).
If you put six pipes in parallel, as soon as one
pipe saturates, the other five carry the load and
then they drop in quick succession.

What temperature should the CPU be for optimal heatpipe cooling?

In theory, a heatsink is designed to work best with a certain cpu.

Strange, all the ones I've seen advertised are for any CPU in multiple types of socket. There must be an optimal temperature that heatpipes work at.

On Sun, 26 Jul 2020 11:16:11 +0100, Chris wrote:

Commander Kinsey wrote:
On Sat, 25 Jul 2020 23:33:54 +0100, Paul wrote:

Commander Kinsey wrote:
Has anybody ever stacked two CPU coolers? First one fitted normally,
then the second welded on top of it. Theoretically, you have twice the
cooling, if it conducts through the first fast enough. I'm referring to
the type with the fan on the side.

Call me, when your solution uses heatpipes.

It does. Two coolers, each with their own 4 heatpipes.

Look at the Zalman completely-passive cooling
computer case, if you want to see how to do it.
It moves heat from one place to another with
heatpipes. The exterior of the case is the
final destination.

https://www.quietpc.com/tnn500af

No no and no. I once bought a "silent power supply" that threw it's heat
out the back with a sticky out heatsink. It went bang after a few months.

Only with heatpipes, can you move heat from
the origin, to the second heatsink, and expect
to get improved performance.

And both the heatsinks have heatpipes running through them.

That's why heatpipes are used, between baseplate
and top-of-fins, so that an excessively-long fin
does some work for you.

It's also why a 50mm tall 40mm square heatsink,
is no more effective than a 25mm tall 40mm square heatsink.
Those are used on chipsets. The upper portion of the
taller unit, has insufficient thermal conduction
for the top of the fins to remove heat. It means
making fins longer and longer (without heatpipes),
is asymptotic. At some point, a longer fin adds
nothing to the solution.

I can't believe that, metal is a very good conductor.

But none is superconducting so there'll always be efficiency losses over
distance. Not all metals are the same which is why sinks are a mix of
copper and aluminium and not made of steel. Any joins also reduce
efficiency. It all adds up to a bad idea.

It was a very short distance from the heatpipes of the bottom one to the heatpipes of the top one.

The top of tall ones can still be hot to touch.

Once you lace the parts together with heatpipes,
then we'll talk. There's a limit to how many
heatpipes can be fitted, and some thought has to be
put into where the heatpipe is moving the heat.

I would have 4 heatpipes running through the bottom half, and 4 through
the top half. There would only be a short interface of normal metal to join the two.

You place the heatpipe at the source, as only if
the heatpipe is in intimate contact, does its 1000x
better performance, work. Just ramming a pipe into
a block with 3 inches of aluminum between the
baseplate and the pipe, that would be useless too.
As the 3 inches of aluminum is a huge thermal
resistance, and the zero resistance of the heatpipe
on top cannot then help. The heatpipes always start
in the baseplate, touching the CPU.

Doesn't have to. The top of the existing heatsink is too hot to touch.
So the heatpipes on the new heatsink will take heat away from there.

Compare it to the temperature of the CPU. It's probably already lost 30-40
°C. Another sink would lose that again.

I touched the block at the bottom where the heatpipes come from and the temperature was very similar.

Anyway I fixed it, by changing the fan, I'd forgotten that some fans are really crap - they can be anything from 1100rpm to 4000rpm. I happened to have a few 3000rpm fans sitting about, so I replaced what looks like about 1100rpm with 3000rpm, and lost 20C of temperature (I don't care about the noise, it's in the garage and operated remotely). What's odd is I used to have one CPU at 65C and one at 75C (with identical coolers), and now the 75C has dropped to 55C. I guess the physical position meant cooler air for one of them.

On Sun, 26 Jul 2020 00:57:30 +0100, Snit wrote:

On 7/25/20 4:17 PM, David_B wrote:
On 25/07/2020 23:47, Commander Kinsey wrote:
On Sat, 25 Jul 2020 23:33:54 +0100, Paul wrote:

Commander Kinsey wrote:
Has anybody ever stacked two CPU coolers? First one fitted normally,
then the second welded on top of it. Theoretically, you have twice the
cooling, if it conducts through the first fast enough. I'm referring to
the type with the fan on the side.

Call me, when your solution uses heatpipes.

It does. Two coolers, each with their own 4 heatpipes.

SNIP FOR BREVITY ONLY

In my opinion, Commander, you are now talking to one of the most
intelligent and experienced Usenet advisers.

Be nice - and heed what he tells you! :-D


I had started a reply to note that, no, you would not get twice the
cooling -- but my response would have been FAR less detailed and
knowledgeable.

I said close to twice the cooling.

On Sun, 26 Jul 2020 00:52:50 +0100, Avila Kap wrote:

On 7/25/2020 2:37 PM, Commander Kinsey wrote:

Doubling the size of the heatsink (and also the number of fans, which
won't blow towards each other) must make a considerable difference. It
will be twice the cooling effect, minus the lack of conduction through
the first heatsink, which I assume will conduct well, being metal and
all that.

What you know about heat sinks one could stuff in a thimble, asshole!

What you know about spelling one could stuff in a thimble, you orifice of a donkey.

Ass: https://upload.wikimedia.org/wikiped...to-CA-2016.jpg

Arse: https://youtu.be/sx6gkKRUUZo

On 26 Jul 2020, Commander Kinsey wrote
(in article op.0oc80rgowdg98l@glass):

On Sun, 26 Jul 2020 00:41:40 +0100, wrote:

On 25 Jul 2020, Commander Kinsey wrote
(in article op.0ob3ngs7wdg98l@glass):

On Sat, 25 Jul 2020 23:08:09 +0100,
wrote:

On 25/07/2020 23:01, Wolffan wrote:
On 25 Jul 2020, Commander Kinsey wrote
(in article op.0obycr1swdg98l@glass):

On Sat, 25 Jul 2020 21:52:31 +0100, wrote:

On 25 Jul 2020, Commander Kinsey wrote
(in article op.0oboc2f2wdg98l@glass):

Has anybody ever stacked two CPU coolers? First one fitted normally,
then
the
second welded on top of it. Theoretically, you have twice the cooling,

no, you won’t.

if it
conducts through the first fast enough. I'm referring to the type with
the
fan on the side.

there are numerous sites out there which cover this; I first
encountered
this
idea in 2001. (Yes, 2001. Not a typo. And it wasn’t a new idea then,
it
was
just new to me.) It turns out that doubling the fans gives from -5%
(that’s
_negative_ five percent, it can make things worse) to +65% airflow,
depending
on numerous factors. (Size of fan, are the fans spinning in the same
direction or in opposite directions, fan speed, how fans are placed
relative
to the heat exchanger, space inside the computer’s case, location of
CPU
relative to sides of computer case, location of other items including
hard
drives, RAM, power supplies, video and/or sound cards, type of case
especially with respect to vents, internal cabling, more.) However,
airflow
and cooling do not necessarily scale together. Merely increasing the
airflow
does not necessarily do much for the cooling, for that you need heat
exchangers attached to the CPU, heat exchangers attached to another
heat
exchanger don’t do much, and airflow is a square effect while heat
exchangers are a cube effect. Airflow maxed out at around +65% for two
fans;
cooling maxed out at about +45%. And it took considerable effort to get
that
+45%, most systems were considerably lower than that. There would be a
_reason_ why liquid cooling is popular. It’s actually simpler and
easier
to
do. Most modern CPUs generate a whole lot less heat than CPUs dating
from
2001 did, so a good way to get a cooler-running system is toi use a
newer
CPU. And to stay way from the heat-producing monsters, notably IBM
Power
CPUs, which have improved no end since then but which are still devices
to
convert electricity into heat, something anyone who ever went near a
G5-
or
a
G4- powered Mac could tell you. (One G4 Mac was called the Windtunnel
because
of the noise level from the fans to keep the CPU cool; one G5 Mac
shipped
with liquid cooling because Apple didn’t want to ship Windtunnel Mk
2...)
IBM is up to Power 8 or 9 or some such now, where G5s were Power 5s,
and
they’re much better behaved, but still...

Doubling the size of the heatsink (and also the number of fans, which
won't
blow towards each other) must make a considerable difference. It will be
twice the cooling effect, minus the lack of conduction through the first
heatsink, which I assume will conduct well, being metal and all that.

You’re not going to get anywhere close to double the cooling. Instead
of
kludging together two fans, just buy one of the properly-designed dual
fan
units out there. (which don’t get twice the cooling of similar
single-fan
designs from the same company, pros can’t get double the cooling
either.
Not even close. Look at the specs for yourself.) Or, if you’re serious
about cooling, use liquid cooling.

What you _will_ get with a dual-fan system is twice the noise. Especially
if
you use small-diameter fans.

Why are you talking down to a Computer Science graduate, Wolffan?

Apple *FAN* BOISE have no experience of such matters. :-P

You are way out of your league here.

Are you not an Apple fan (can't call you a boy at your age) yourself?

he’s an idiot.

Apart from believing in god and using Apples, no he isn't. He's just down the
road from me (well 500 miles).

He attempted to post authoritatively about IPs, when he not merely didn’t
know the difference between IPv4 and IPv6, he _thought that x.x.x.x was a
valid IP address_. Yes, really. He’s an idiot.

On Sun, 26 Jul 2020 15:40:34 +0100, Wolffan wrote:

On 26 Jul 2020, Commander Kinsey wrote
(in article op.0oc80rgowdg98l@glass):

On Sun, 26 Jul 2020 00:41:40 +0100, wrote:

On 25 Jul 2020, Commander Kinsey wrote
(in article op.0ob3ngs7wdg98l@glass):

On Sat, 25 Jul 2020 23:08:09 +0100,
wrote:

On 25/07/2020 23:01, Wolffan wrote:
On 25 Jul 2020, Commander Kinsey wrote
(in article op.0obycr1swdg98l@glass):

On Sat, 25 Jul 2020 21:52:31 +0100, wrote:

On 25 Jul 2020, Commander Kinsey wrote
(in article op.0oboc2f2wdg98l@glass):

Has anybody ever stacked two CPU coolers? First one fitted normally,
then
the
second welded on top of it. Theoretically, you have twice the cooling,

no, you won’t.

if it
conducts through the first fast enough. I'm referring to the type with
the
fan on the side.

there are numerous sites out there which cover this; I first
encountered
this
idea in 2001. (Yes, 2001. Not a typo. And it wasn’t a new idea then,
it
was
just new to me.) It turns out that doubling the fans gives from -5%
(that’s
_negative_ five percent, it can make things worse) to +65% airflow,
depending
on numerous factors. (Size of fan, are the fans spinning in the same
direction or in opposite directions, fan speed, how fans are placed
relative
to the heat exchanger, space inside the computer’s case, location of
CPU
relative to sides of computer case, location of other items including
hard
drives, RAM, power supplies, video and/or sound cards, type of case
especially with respect to vents, internal cabling, more.) However,
airflow
and cooling do not necessarily scale together. Merely increasing the
airflow
does not necessarily do much for the cooling, for that you need heat
exchangers attached to the CPU, heat exchangers attached to another
heat
exchanger don’t do much, and airflow is a square effect while heat
exchangers are a cube effect. Airflow maxed out at around +65% for two
fans;
cooling maxed out at about +45%. And it took considerable effort to get
that
+45%, most systems were considerably lower than that. There would be a
_reason_ why liquid cooling is popular. It’s actually simpler and
easier
to
do. Most modern CPUs generate a whole lot less heat than CPUs dating
from
2001 did, so a good way to get a cooler-running system is toi use a
newer
CPU. And to stay way from the heat-producing monsters, notably IBM
Power
CPUs, which have improved no end since then but which are still devices
to
convert electricity into heat, something anyone who ever went near a
G5-
or
a
G4- powered Mac could tell you. (One G4 Mac was called the Windtunnel
because
of the noise level from the fans to keep the CPU cool; one G5 Mac
shipped
with liquid cooling because Apple didn’t want to ship Windtunnel Mk
2...)
IBM is up to Power 8 or 9 or some such now, where G5s were Power 5s,
and
they’re much better behaved, but still...

Doubling the size of the heatsink (and also the number of fans, which
won't
blow towards each other) must make a considerable difference. It will be
twice the cooling effect, minus the lack of conduction through the first
heatsink, which I assume will conduct well, being metal and all that.

You’re not going to get anywhere close to double the cooling. Instead
of
kludging together two fans, just buy one of the properly-designed dual
fan
units out there. (which don’t get twice the cooling of similar
single-fan
designs from the same company, pros can’t get double the cooling
either.
Not even close. Look at the specs for yourself.) Or, if you’re serious
about cooling, use liquid cooling.

What you _will_ get with a dual-fan system is twice the noise.. Especially
if
you use small-diameter fans.

Why are you talking down to a Computer Science graduate, Wolffan?

Apple *FAN* BOISE have no experience of such matters. :-P

You are way out of your league here.

Are you not an Apple fan (can't call you a boy at your age) yourself?

he’s an idiot.

Apart from believing in god and using Apples, no he isn't. He's just down the
road from me (well 500 miles).

He attempted to post authoritatively about IPs, when he not merely didn’t
know the difference between IPv4 and IPv6, he _thought that x.x.x.x was a
valid IP address_. Yes, really. He’s an idiot.

I guess using Apples he never encounters IPs. All the important stuff is hidden from you on the mickey mouse machines.

On 26 Jul 2020, Commander Kinsey wrote
(in article op.0oc9vhsewdg98l@glass):

On Sun, 26 Jul 2020 15:40:34 +0100, wrote:

On 26 Jul 2020, Commander Kinsey wrote
(in article op.0oc80rgowdg98l@glass):

On Sun, 26 Jul 2020 00:41:40 +0100, wrote:

On 25 Jul 2020, Commander Kinsey wrote
(in article op.0ob3ngs7wdg98l@glass):

On Sat, 25 Jul 2020 23:08:09 +0100,
wrote:

On 25/07/2020 23:01, Wolffan wrote:
On 25 Jul 2020, Commander Kinsey wrote
(in article op.0obycr1swdg98l@glass):

On Sat, 25 Jul 2020 21:52:31 +0100,
wrote:

On 25 Jul 2020, Commander Kinsey wrote
(in article op.0oboc2f2wdg98l@glass):

Has anybody ever stacked two CPU coolers? First one fitted normally,
then
the
second welded on top of it. Theoretically, you have twice the
cooling,

no, you won’t.

if it
conducts through the first fast enough. I'm referring to the type
with
the
fan on the side.

there are numerous sites out there which cover this; I first
encountered
this
idea in 2001. (Yes, 2001. Not a typo. And it wasn’t a new idea
then,
it
was
just new to me.) It turns out that doubling the fans gives from -5%
(that’s
_negative_ five percent, it can make things worse) to +65% airflow,
depending
on numerous factors. (Size of fan, are the fans spinning in the same
direction or in opposite directions, fan speed, how fans are placed
relative
to the heat exchanger, space inside the computer’s case, location
of
CPU
relative to sides of computer case, location of other items including
hard
drives, RAM, power supplies, video and/or sound cards, type of case
especially with respect to vents, internal cabling, more.) However,
airflow
and cooling do not necessarily scale together. Merely increasing the
airflow
does not necessarily do much for the cooling, for that you need heat
exchangers attached to the CPU, heat exchangers attached to another
heat
exchanger don’t do much, and airflow is a square effect while heat
exchangers are a cube effect. Airflow maxed out at around +65% for
two
fans;
cooling maxed out at about +45%. And it took considerable effort to
get
that
+45%, most systems were considerably lower than that. There would be
a
_reason_ why liquid cooling is popular. It’s actually simpler and
easier
to
do. Most modern CPUs generate a whole lot less heat than CPUs dating
from
2001 did, so a good way to get a cooler-running system is toi use a
newer
CPU. And to stay way from the heat-producing monsters, notably IBM
Power
CPUs, which have improved no end since then but which are still
devices
to
convert electricity into heat, something anyone who ever went near a
G5-
or
a
G4- powered Mac could tell you. (One G4 Mac was called the Windtunnel
because
of the noise level from the fans to keep the CPU cool; one G5 Mac
shipped
with liquid cooling because Apple didn’t want to ship Windtunnel Mk
2...)
IBM is up to Power 8 or 9 or some such now, where G5s were Power 5s,
and
they’re much better behaved, but still...

Doubling the size of the heatsink (and also the number of fans, which
won't
blow towards each other) must make a considerable difference. It will
be
twice the cooling effect, minus the lack of conduction through the
first
heatsink, which I assume will conduct well, being metal and all that.

You’re not going to get anywhere close to double the cooling. Instead
of
kludging together two fans, just buy one of the properly-designed dual
fan
units out there. (which don’t get twice the cooling of similar
single-fan
designs from the same company, pros can’t get double the cooling
either.
Not even close. Look at the specs for yourself.) Or, if you’re
serious
about cooling, use liquid cooling.

What you _will_ get with a dual-fan system is twice the noise.
Especially
if
you use small-diameter fans.

Why are you talking down to a Computer Science graduate, Wolffan?

Apple *FAN* BOISE have no experience of such matters. :-P

You are way out of your league here.

Are you not an Apple fan (can't call you a boy at your age) yourself?

he’s an idiot.

Apart from believing in god and using Apples, no he isn't. He's just down
the
road from me (well 500 miles).

He attempted to post authoritatively about IPs, when he not merely didn’t
know the difference between IPv4 and IPv6, he _thought that x.x.x.x was a
valid IP address_. Yes, really. He’s an idiot.

I guess using Apples he never encounters IPs. All the important stuff is
hidden from you on the mickey mouse machines.

Nope. Ips are quite visible in the Network pane of System Preferences. There
are panes for setting your IPv4 and v6 addresses, for DNS, proxies, 802.1X,
even for playing with the MAC. Ethernet has one set of panes, 802.11 wireless
another, there are others for other types of network connections. He’s
sufficiently idiotic and pig-ignorant that he he’d bother to go to his
Apple menu, select System Preferences, click on Networks, click on the
network connection of his choice, and have a look. And, when his idiocy was
pointed out to him, he denied it, and when evidence of his idiocy was
provided (a MID and a quote from his post, IIRC) he ran away. Nor is this the
only example of his idiocy, just an example easily shown. Most good news
clients have a built-in search engine; in the Hog, I can search for and find
any string in any post on any newsgroup in my system list. Finding
‘x.x.x.x’ in a.c.w, or any other newsgroup, is trivial. I don’t know if
your client has similar abilities. He has perpetuated many idiocies over a
prolonged period. He’s an idiot.

On Sat, 25 Jul 2020 19:01:34 +0100, "Commander Kinsey"
wrote:

Has anybody ever stacked two CPU coolers? First one fitted normally, then the second welded on top of it. Theoretically, you have twice the cooling, if it conducts through the first fast enough. I'm referring to the type with the fan on the side.

I have a Noctua NH-D15 - https://noctua.at/en/nh-d15 - which sort of
addresses your question by putting two fans on one cooler. It sits on
an AMD Ryzen 5 3600.
I have resistors in cicuit to slow the fans and both the case fans are
slowed, too. The NVIDIA Quadro P2000 video card has a tiny fan on it.
The PSU is fanless.
The whole lot makes hardly any noise. Much quieter than when I had two
fanless graphics cards in before I got the P2000.