jlarkin@highlandsniptechnology.com wrote:
> On Sun, 17 Apr 2022 17:50:59 -0000 (UTC),
> DecadentLinuxUserNumeroUno@decadence.org wrote:
>
>> Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote in
>> news:t3hijn$cus$1@dont-email.me:
>>
>>> On a sunny day (Sun, 17 Apr 2022 09:25:41 -0700) it happened
>>> jlarkin@highlandsniptechnology.com wrote in
>>> <thfo5ht952906bo9837snjolpjfd2lsc00@4ax.com>:
>>>
>>>> On Sun, 17 Apr 2022 09:10:41 -0700,
>>>> jlarkin@highlandsniptechnology.com wrote:
>>>>
>>>>> On Sun, 17 Apr 2022 15:55:21 -0000 (UTC),
>>>>> DecadentLinuxUserNumeroUno@decadence.org wrote:
>>>>>
>>>>>> Ricky <gnuarm.deletethisbit@gmail.com> wrote in
>>>>>> news:3f3e0e0f-175e-4d27-be95-401418cc7e54n@googlegroups.com:
>>>>>>
>>>>>>> The large surface area of the long, skinny fins are perfect
>>>>>>> coupling between the low thermal resistance of the heat sink
>>>>>>> and the relatively high thermal conductivity of the fin/air
>>>>>>> contact.
>>>>>>
>>>>>> The word(s) for today is "boundary layer".
>>>>>>
>>>>>> <https://www.heatsinkcalculator.com/blog/wp-
>>>>>> content/uploads/2016/05/effect_of_boundary_laher_thickness.png>
>>>>>>
>>>>>> <https://www.heatsinkcalculator.com/blog/top-3-mistakes-made-when
>>>>>> - selecting-a-heat-sink/>
>>>>>>
>>>>>> Slow air would pass right over a close fin spaced sink. High
>>>>>> speed
>>>>>> forced air is required when the fins get that closely spaced.
>>>>>
>>>>>
>>>>> Right. Viscous drag will keep air from flowing between tall,
>>>>> closely spaced fins. It will have to be ducted and forced, or it
>>>>> will go around.
>>>>>
>>>>> The limiting case, more and more denser and thinner fins,
>>>>> volumetric air flow will approach zero.
>>>>>
>>>>> My general rule is that a heat sink should reduce the native air
>>>>> flow by about half. Neither zero nor 100% does any cooling.
>>>>
>>>> And of course, the tips of tall thin fins have a high thermal
>>>> resistance to the baseplate, so run at about inlet air temp, so
>>>> restrict air flow without contributing much coolong. My 50% number
>>>> is useless if the air flow is restricted without corresponding
>>>> cooling.
>>>>
>>>> There is no limit to how bad a heat sink you can design. A solid
>>>> aluminum brick is pretty bad.
>>>
>>> This works great:
>>> http://panteltje.com/pub/big_3kg_heatsink_IMG_3745.GIF
>>>
>>> BTW that is a rubidum reference on top of it.
>>>
>>
>> That is a very poor heat sink. Essentialy it conduction cools the
>> device it is mounted to, but not much gets radiated away. More like
>> a homogenizer.
>>
>> There is a reason that motorcycle air cooled cylinder jugs and
>> heads are NOT painted.
>
> Radiation cooling goes as the 4th power of the temp difference between
> the sink and the universe. Since semiconductors can't be allowed to
> get very hot above ambient, rad cooling is usually minor. Inside a
> metal box, a lot of the radiation is trapped and reflects back.

The emission from a black body goes like T**4, so the thermal coupling
between two surfaces goes like the difference, i.e. T1**4 - T2**4. For
small temperature differences, that's basically 4 * T**3 * delta T.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

jlarkin@highlandsniptechnology.com wrote in
news:btro5hl6gr3pp1ph77olc2a2c8k5ihh017@4ax.com:

> On Sun, 17 Apr 2022 17:50:59 -0000 (UTC),
> DecadentLinuxUserNumeroUno@decadence.org wrote:
>
>>Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote in
>>news:t3hijn$cus$1@dont-email.me:
>>
>>> On a sunny day (Sun, 17 Apr 2022 09:25:41 -0700) it happened
>>> jlarkin@highlandsniptechnology.com wrote in
>>> <thfo5ht952906bo9837snjolpjfd2lsc00@4ax.com>:
>>>
>>>>On Sun, 17 Apr 2022 09:10:41 -0700,
>>>>jlarkin@highlandsniptechnology.com wrote:
>>>>
>>>>>On Sun, 17 Apr 2022 15:55:21 -0000 (UTC),
>>>>>DecadentLinuxUserNumeroUno@decadence.org wrote:
>>>>>
>>>>>>Ricky <gnuarm.deletethisbit@gmail.com> wrote in
>>>>>>news:3f3e0e0f-175e-4d27-be95-401418cc7e54n@googlegroups.com:
>>>>>>
>>>>>>> The large surface area of the long, skinny fins are perfect
>>>>>>> coupling between the low thermal resistance of the heat sink
>>>>>>> and the relatively high thermal conductivity of the fin/air
>>>>>>> contact.
>>>>>>
>>>>>> The word(s) for today is "boundary layer".
>>>>>>
>>>>>><https://www.heatsinkcalculator.com/blog/wp-
>>>>>>content/uploads/2016/05/effect_of_boundary_laher_thickness.png>
>>>>>>
>>>>>><https://www.heatsinkcalculator.com/blog/top-3-mistakes-made-wh
>>>>>>en - selecting-a-heat-sink/>
>>>>>>
>>>>>> Slow air would pass right over a close fin spaced sink.
>>>>>> High speed
>>>>>>forced air is required when the fins get that closely spaced.
>>>>>
>>>>>
>>>>>Right. Viscous drag will keep air from flowing between tall,
>>>>>closely spaced fins. It will have to be ducted and forced, or
>>>>>it will go around.
>>>>>
>>>>>The limiting case, more and more denser and thinner fins,
>>>>>volumetric air flow will approach zero.
>>>>>
>>>>>My general rule is that a heat sink should reduce the native
>>>>>air flow by about half. Neither zero nor 100% does any cooling.
>>>>
>>>>And of course, the tips of tall thin fins have a high thermal
>>>>resistance to the baseplate, so run at about inlet air temp, so
>>>>restrict air flow without contributing much coolong. My 50%
>>>>number is useless if the air flow is restricted without
>>>>corresponding cooling.
>>>>
>>>>There is no limit to how bad a heat sink you can design. A solid
>>>>aluminum brick is pretty bad.
>>>
>>> This works great:
>>> http://panteltje.com/pub/big_3kg_heatsink_IMG_3745.GIF
>>>
>>> BTW that is a rubidum reference on top of it.
>>>
>>
>> That is a very poor heat sink. Essentialy it conduction cools
>> the
>>device it is mounted to, but not much gets radiated away. More
>>like a homogenizer.
>>
>> There is a reason that motorcycle air cooled cylinder jugs and
>>heads are NOT painted.
>
> Radiation cooling goes as the 4th power of the temp difference
> between the sink and the universe. Since semiconductors can't be
> allowed to get very hot above ambient, rad cooling is usually
> minor. Inside a metal box, a lot of the radiation is trapped and
> reflects back.
>
All of the MIDS JTRS tactical transcievers in the US and ally
military are all populated with canned, conduction cooled cards.
Whether it is being slid into an F-18, or an F-35 or an F-22 they all
go on the same tray Which has the PS unit and the MIDS unit and the
RF amplifier unit. It is the most advanced SDR there is. ALL
conduction cooled 'cards'. All temps get homogenized throughout the
init. The RF amp is the only part that has air passages ported
through it.

<https://www.dote.osd.mil/Portals/97/pub/reports/FY2010/dod/2010mids.
pdf?ver=2019-08-22-112846-223>

That is a micro sized VAX but way faster than a normal VAX.
It manages AEGIS targetting and all of the battlefield waveforms.
Mainly the still in use, still not crypto broken Link 16 waveform.

On Sunday, April 17, 2022 at 4:49:48 PM UTC-4, Phil Hobbs wrote:
> jla...@highlandsniptechnology.com wrote:
> > On Sun, 17 Apr 2022 17:50:59 -0000 (UTC),
> > DecadentLinux...@decadence.org wrote:
> >
> >> Jan Panteltje <pNaonSt...@yahoo.com> wrote in
> >> news:t3hijn$cus$1...@dont-email.me:
> >>
> >>> On a sunny day (Sun, 17 Apr 2022 09:25:41 -0700) it happened
> >>> jla...@highlandsniptechnology.com wrote in
> >>> <thfo5ht952906bo98...@4ax.com>:
> >>>
> >>>> On Sun, 17 Apr 2022 09:10:41 -0700,
> >>>> jla...@highlandsniptechnology.com wrote:
> >>>>
> >>>>> On Sun, 17 Apr 2022 15:55:21 -0000 (UTC),
> >>>>> DecadentLinux...@decadence.org wrote:
> >>>>>
> >>>>>> Ricky <gnuarm.del...@gmail.com> wrote in
> >>>>>> news:3f3e0e0f-175e-4d27...@googlegroups.com:
> >>>>>>
> >>>>>>> The large surface area of the long, skinny fins are perfect
> >>>>>>> coupling between the low thermal resistance of the heat sink
> >>>>>>> and the relatively high thermal conductivity of the fin/air
> >>>>>>> contact.
> >>>>>>
> >>>>>> The word(s) for today is "boundary layer".
> >>>>>>
> >>>>>> <https://www.heatsinkcalculator.com/blog/wp-
> >>>>>> content/uploads/2016/05/effect_of_boundary_laher_thickness.png>
> >>>>>>
> >>>>>> <https://www.heatsinkcalculator.com/blog/top-3-mistakes-made-when
> >>>>>> - selecting-a-heat-sink/>
> >>>>>>
> >>>>>> Slow air would pass right over a close fin spaced sink. High
> >>>>>> speed
> >>>>>> forced air is required when the fins get that closely spaced.
> >>>>>
> >>>>>
> >>>>> Right. Viscous drag will keep air from flowing between tall,
> >>>>> closely spaced fins. It will have to be ducted and forced, or it
> >>>>> will go around.
> >>>>>
> >>>>> The limiting case, more and more denser and thinner fins,
> >>>>> volumetric air flow will approach zero.
> >>>>>
> >>>>> My general rule is that a heat sink should reduce the native air
> >>>>> flow by about half. Neither zero nor 100% does any cooling.
> >>>>
> >>>> And of course, the tips of tall thin fins have a high thermal
> >>>> resistance to the baseplate, so run at about inlet air temp, so
> >>>> restrict air flow without contributing much coolong. My 50% number
> >>>> is useless if the air flow is restricted without corresponding
> >>>> cooling.
> >>>>
> >>>> There is no limit to how bad a heat sink you can design. A solid
> >>>> aluminum brick is pretty bad.
> >>>
> >>> This works great:
> >>> http://panteltje.com/pub/big_3kg_heatsink_IMG_3745.GIF
> >>>
> >>> BTW that is a rubidum reference on top of it.
> >>>
> >>
> >> That is a very poor heat sink. Essentialy it conduction cools the
> >> device it is mounted to, but not much gets radiated away. More like
> >> a homogenizer.
> >>
> >> There is a reason that motorcycle air cooled cylinder jugs and
> >> heads are NOT painted.
> >
> > Radiation cooling goes as the 4th power of the temp difference between
> > the sink and the universe. Since semiconductors can't be allowed to
> > get very hot above ambient, rad cooling is usually minor. Inside a
> > metal box, a lot of the radiation is trapped and reflects back.
> The emission from a black body goes like T**4, so the thermal coupling
> between two surfaces goes like the difference, i.e. T1**4 - T2**4. For
> small temperature differences, that's basically 4 * T**3 * delta T.

Don't forget to use absolute temperature. I remember a discussion here about inflate-gate where it took four iterations on the calculations and a large number of posts before anyone got the math right, because both the temperature and the pressure had to be absolute, not relative. Basically, there are two independent mistakes that could be made and all three erroneous calculations were done before the correct calculation was stumbled upon.

--

Rick C.

--- Get 1,000 miles of free Supercharging
--- Tesla referral code - https://ts.la/richard11209

On Sunday, April 17, 2022 at 6:23:37 PM UTC-4, DecadentLinux...@decadence.org wrote:
> jla...@highlandsniptechnology.com wrote in
> news:btro5hl6gr3pp1ph7...@4ax.com:
> > On Sun, 17 Apr 2022 17:50:59 -0000 (UTC),
> > DecadentLinux...@decadence.org wrote:
> >
> >>Jan Panteltje <pNaonSt...@yahoo.com> wrote in
> >>news:t3hijn$cus$1...@dont-email.me:
> >>
> >>> On a sunny day (Sun, 17 Apr 2022 09:25:41 -0700) it happened
> >>> jla...@highlandsniptechnology.com wrote in
> >>> <thfo5ht952906bo98...@4ax.com>:
> >>>
> >>>>On Sun, 17 Apr 2022 09:10:41 -0700,
> >>>>jla...@highlandsniptechnology.com wrote:
> >>>>
> >>>>>On Sun, 17 Apr 2022 15:55:21 -0000 (UTC),
> >>>>>DecadentLinux...@decadence.org wrote:
> >>>>>
> >>>>>>Ricky <gnuarm.del...@gmail.com> wrote in
> >>>>>>news:3f3e0e0f-175e-4d27...@googlegroups.com:
> >>>>>>
> >>>>>>> The large surface area of the long, skinny fins are perfect
> >>>>>>> coupling between the low thermal resistance of the heat sink
> >>>>>>> and the relatively high thermal conductivity of the fin/air
> >>>>>>> contact.
> >>>>>>
> >>>>>> The word(s) for today is "boundary layer".
> >>>>>>
> >>>>>><https://www.heatsinkcalculator.com/blog/wp-
> >>>>>>content/uploads/2016/05/effect_of_boundary_laher_thickness.png>
> >>>>>>
> >>>>>><https://www.heatsinkcalculator.com/blog/top-3-mistakes-made-wh
> >>>>>>en - selecting-a-heat-sink/>
> >>>>>>
> >>>>>> Slow air would pass right over a close fin spaced sink.
> >>>>>> High speed
> >>>>>>forced air is required when the fins get that closely spaced.
> >>>>>
> >>>>>
> >>>>>Right. Viscous drag will keep air from flowing between tall,
> >>>>>closely spaced fins. It will have to be ducted and forced, or
> >>>>>it will go around.
> >>>>>
> >>>>>The limiting case, more and more denser and thinner fins,
> >>>>>volumetric air flow will approach zero.
> >>>>>
> >>>>>My general rule is that a heat sink should reduce the native
> >>>>>air flow by about half. Neither zero nor 100% does any cooling.
> >>>>
> >>>>And of course, the tips of tall thin fins have a high thermal
> >>>>resistance to the baseplate, so run at about inlet air temp, so
> >>>>restrict air flow without contributing much coolong. My 50%
> >>>>number is useless if the air flow is restricted without
> >>>>corresponding cooling.
> >>>>
> >>>>There is no limit to how bad a heat sink you can design. A solid
> >>>>aluminum brick is pretty bad.
> >>>
> >>> This works great:
> >>> http://panteltje.com/pub/big_3kg_heatsink_IMG_3745.GIF
> >>>
> >>> BTW that is a rubidum reference on top of it.
> >>>
> >>
> >> That is a very poor heat sink. Essentialy it conduction cools
> >> the
> >>device it is mounted to, but not much gets radiated away. More
> >>like a homogenizer.
> >>
> >> There is a reason that motorcycle air cooled cylinder jugs and
> >>heads are NOT painted.
> >
> > Radiation cooling goes as the 4th power of the temp difference
> > between the sink and the universe. Since semiconductors can't be
> > allowed to get very hot above ambient, rad cooling is usually
> > minor. Inside a metal box, a lot of the radiation is trapped and
> > reflects back.
> >
> All of the MIDS JTRS tactical transcievers in the US and ally
> military are all populated with canned, conduction cooled cards.
> Whether it is being slid into an F-18, or an F-35 or an F-22 they all
> go on the same tray Which has the PS unit and the MIDS unit and the
> RF amplifier unit. It is the most advanced SDR there is. ALL
> conduction cooled 'cards'. All temps get homogenized throughout the
> init. The RF amp is the only part that has air passages ported
> through it.
>
> <https://www.dote.osd.mil/Portals/97/pub/reports/FY2010/dod/2010mids.
> pdf?ver=2019-08-22-112846-223>
>
> That is a micro sized VAX but way faster than a normal VAX.
> It manages AEGIS targetting and all of the battlefield waveforms.
> Mainly the still in use, still not crypto broken Link 16 waveform.

I wonder when it will support full self driving?

--

Rick C.

--+ Get 1,000 miles of free Supercharging
--+ Tesla referral code - https://ts.la/richard11209

On Sun, 17 Apr 2022 16:49:40 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>jlarkin@highlandsniptechnology.com wrote:
>> On Sun, 17 Apr 2022 17:50:59 -0000 (UTC),
>> DecadentLinuxUserNumeroUno@decadence.org wrote:
>>
>>> Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote in
>>> news:t3hijn$cus$1@dont-email.me:
>>>
>>>> On a sunny day (Sun, 17 Apr 2022 09:25:41 -0700) it happened
>>>> jlarkin@highlandsniptechnology.com wrote in
>>>> <thfo5ht952906bo9837snjolpjfd2lsc00@4ax.com>:
>>>>
>>>>> On Sun, 17 Apr 2022 09:10:41 -0700,
>>>>> jlarkin@highlandsniptechnology.com wrote:
>>>>>
>>>>>> On Sun, 17 Apr 2022 15:55:21 -0000 (UTC),
>>>>>> DecadentLinuxUserNumeroUno@decadence.org wrote:
>>>>>>
>>>>>>> Ricky <gnuarm.deletethisbit@gmail.com> wrote in
>>>>>>> news:3f3e0e0f-175e-4d27-be95-401418cc7e54n@googlegroups.com:
>>>>>>>
>>>>>>>> The large surface area of the long, skinny fins are perfect
>>>>>>>> coupling between the low thermal resistance of the heat sink
>>>>>>>> and the relatively high thermal conductivity of the fin/air
>>>>>>>> contact.
>>>>>>>
>>>>>>> The word(s) for today is "boundary layer".
>>>>>>>
>>>>>>> <https://www.heatsinkcalculator.com/blog/wp-
>>>>>>> content/uploads/2016/05/effect_of_boundary_laher_thickness.png>
>>>>>>>
>>>>>>> <https://www.heatsinkcalculator.com/blog/top-3-mistakes-made-when
>>>>>>> - selecting-a-heat-sink/>
>>>>>>>
>>>>>>> Slow air would pass right over a close fin spaced sink. High
>>>>>>> speed
>>>>>>> forced air is required when the fins get that closely spaced.
>>>>>>
>>>>>>
>>>>>> Right. Viscous drag will keep air from flowing between tall,
>>>>>> closely spaced fins. It will have to be ducted and forced, or it
>>>>>> will go around.
>>>>>>
>>>>>> The limiting case, more and more denser and thinner fins,
>>>>>> volumetric air flow will approach zero.
>>>>>>
>>>>>> My general rule is that a heat sink should reduce the native air
>>>>>> flow by about half. Neither zero nor 100% does any cooling.
>>>>>
>>>>> And of course, the tips of tall thin fins have a high thermal
>>>>> resistance to the baseplate, so run at about inlet air temp, so
>>>>> restrict air flow without contributing much coolong. My 50% number
>>>>> is useless if the air flow is restricted without corresponding
>>>>> cooling.
>>>>>
>>>>> There is no limit to how bad a heat sink you can design. A solid
>>>>> aluminum brick is pretty bad.
>>>>
>>>> This works great:
>>>> http://panteltje.com/pub/big_3kg_heatsink_IMG_3745.GIF
>>>>
>>>> BTW that is a rubidum reference on top of it.
>>>>
>>>
>>> That is a very poor heat sink. Essentialy it conduction cools the
>>> device it is mounted to, but not much gets radiated away. More like
>>> a homogenizer.
>>>
>>> There is a reason that motorcycle air cooled cylinder jugs and
>>> heads are NOT painted.
>>
>> Radiation cooling goes as the 4th power of the temp difference between
>> the sink and the universe. Since semiconductors can't be allowed to
>> get very hot above ambient, rad cooling is usually minor. Inside a
>> metal box, a lot of the radiation is trapped and reflects back.
>
>The emission from a black body goes like T**4, so the thermal coupling
>between two surfaces goes like the difference, i.e. T1**4 - T2**4. For
>small temperature differences, that's basically 4 * T**3 * delta T.
>
>Cheers
>
>Phil Hobbs

I wrote a little PowerBasic program to do the calc.

https://www.dropbox.com/s/6a70p72e9yltsj7/Radcool2.EXE?dl=0

It uses the equation from Reference Data for Radio Engineers.

It's still pretty small for semiconductors on heat sinks.

--

I yam what I yam - Popeye

jlarkin@highlandsniptechnology.com wrote:
> On Sun, 17 Apr 2022 16:49:40 -0400, Phil Hobbs
> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>
>> jlarkin@highlandsniptechnology.com wrote:
>>> On Sun, 17 Apr 2022 17:50:59 -0000 (UTC),
>>> DecadentLinuxUserNumeroUno@decadence.org wrote:
>>>
>>>> Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote in
>>>> news:t3hijn$cus$1@dont-email.me:
>>>>
>>>>> On a sunny day (Sun, 17 Apr 2022 09:25:41 -0700) it happened
>>>>> jlarkin@highlandsniptechnology.com wrote in
>>>>> <thfo5ht952906bo9837snjolpjfd2lsc00@4ax.com>:
>>>>>
>>>>>> On Sun, 17 Apr 2022 09:10:41 -0700,
>>>>>> jlarkin@highlandsniptechnology.com wrote:
>>>>>>
>>>>>>> On Sun, 17 Apr 2022 15:55:21 -0000 (UTC),
>>>>>>> DecadentLinuxUserNumeroUno@decadence.org wrote:
>>>>>>>
>>>>>>>> Ricky <gnuarm.deletethisbit@gmail.com> wrote in
>>>>>>>> news:3f3e0e0f-175e-4d27-be95-401418cc7e54n@googlegroups.com:
>>>>>>>>
>>>>>>>>> The large surface area of the long, skinny fins are perfect
>>>>>>>>> coupling between the low thermal resistance of the heat sink
>>>>>>>>> and the relatively high thermal conductivity of the fin/air
>>>>>>>>> contact.
>>>>>>>>
>>>>>>>> The word(s) for today is "boundary layer".
>>>>>>>>
>>>>>>>> <https://www.heatsinkcalculator.com/blog/wp-
>>>>>>>> content/uploads/2016/05/effect_of_boundary_laher_thickness.png>
>>>>>>>>
>>>>>>>> <https://www.heatsinkcalculator.com/blog/top-3-mistakes-made-when
>>>>>>>> - selecting-a-heat-sink/>
>>>>>>>>
>>>>>>>> Slow air would pass right over a close fin spaced sink. High
>>>>>>>> speed
>>>>>>>> forced air is required when the fins get that closely spaced.
>>>>>>>
>>>>>>>
>>>>>>> Right. Viscous drag will keep air from flowing between tall,
>>>>>>> closely spaced fins. It will have to be ducted and forced, or it
>>>>>>> will go around.
>>>>>>>
>>>>>>> The limiting case, more and more denser and thinner fins,
>>>>>>> volumetric air flow will approach zero.
>>>>>>>
>>>>>>> My general rule is that a heat sink should reduce the native air
>>>>>>> flow by about half. Neither zero nor 100% does any cooling.
>>>>>>
>>>>>> And of course, the tips of tall thin fins have a high thermal
>>>>>> resistance to the baseplate, so run at about inlet air temp, so
>>>>>> restrict air flow without contributing much coolong. My 50% number
>>>>>> is useless if the air flow is restricted without corresponding
>>>>>> cooling.
>>>>>>
>>>>>> There is no limit to how bad a heat sink you can design. A solid
>>>>>> aluminum brick is pretty bad.
>>>>>
>>>>> This works great:
>>>>> http://panteltje.com/pub/big_3kg_heatsink_IMG_3745.GIF
>>>>>
>>>>> BTW that is a rubidum reference on top of it.
>>>>>
>>>>
>>>> That is a very poor heat sink. Essentialy it conduction cools the
>>>> device it is mounted to, but not much gets radiated away. More like
>>>> a homogenizer.
>>>>
>>>> There is a reason that motorcycle air cooled cylinder jugs and
>>>> heads are NOT painted.
>>>
>>> Radiation cooling goes as the 4th power of the temp difference between
>>> the sink and the universe. Since semiconductors can't be allowed to
>>> get very hot above ambient, rad cooling is usually minor. Inside a
>>> metal box, a lot of the radiation is trapped and reflects back.
>>
>> The emission from a black body goes like T**4, so the thermal coupling
>> between two surfaces goes like the difference, i.e. T1**4 - T2**4. For
>> small temperature differences, that's basically 4 * T**3 * delta T.
>>
>> Cheers
>>
>> Phil Hobbs
>
> I wrote a little PowerBasic program to do the calc.
>
> https://www.dropbox.com/s/6a70p72e9yltsj7/Radcool2.EXE?dl=0
>
> It uses the equation from Reference Data for Radio Engineers.
>
> It's still pretty small for semiconductors on heat sinks.

For two black bodies at 300K, the thermal impedance of radiation is
about the same as 6 mm of air.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Sun, 17 Apr 2022 21:24:40 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>jlarkin@highlandsniptechnology.com wrote:
>> On Sun, 17 Apr 2022 16:49:40 -0400, Phil Hobbs
>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>>
>>> jlarkin@highlandsniptechnology.com wrote:
>>>> On Sun, 17 Apr 2022 17:50:59 -0000 (UTC),
>>>> DecadentLinuxUserNumeroUno@decadence.org wrote:
>>>>
>>>>> Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote in
>>>>> news:t3hijn$cus$1@dont-email.me:
>>>>>
>>>>>> On a sunny day (Sun, 17 Apr 2022 09:25:41 -0700) it happened
>>>>>> jlarkin@highlandsniptechnology.com wrote in
>>>>>> <thfo5ht952906bo9837snjolpjfd2lsc00@4ax.com>:
>>>>>>
>>>>>>> On Sun, 17 Apr 2022 09:10:41 -0700,
>>>>>>> jlarkin@highlandsniptechnology.com wrote:
>>>>>>>
>>>>>>>> On Sun, 17 Apr 2022 15:55:21 -0000 (UTC),
>>>>>>>> DecadentLinuxUserNumeroUno@decadence.org wrote:
>>>>>>>>
>>>>>>>>> Ricky <gnuarm.deletethisbit@gmail.com> wrote in
>>>>>>>>> news:3f3e0e0f-175e-4d27-be95-401418cc7e54n@googlegroups.com:
>>>>>>>>>
>>>>>>>>>> The large surface area of the long, skinny fins are perfect
>>>>>>>>>> coupling between the low thermal resistance of the heat sink
>>>>>>>>>> and the relatively high thermal conductivity of the fin/air
>>>>>>>>>> contact.
>>>>>>>>>
>>>>>>>>> The word(s) for today is "boundary layer".
>>>>>>>>>
>>>>>>>>> <https://www.heatsinkcalculator.com/blog/wp-
>>>>>>>>> content/uploads/2016/05/effect_of_boundary_laher_thickness.png>
>>>>>>>>>
>>>>>>>>> <https://www.heatsinkcalculator.com/blog/top-3-mistakes-made-when
>>>>>>>>> - selecting-a-heat-sink/>
>>>>>>>>>
>>>>>>>>> Slow air would pass right over a close fin spaced sink. High
>>>>>>>>> speed
>>>>>>>>> forced air is required when the fins get that closely spaced.
>>>>>>>>
>>>>>>>>
>>>>>>>> Right. Viscous drag will keep air from flowing between tall,
>>>>>>>> closely spaced fins. It will have to be ducted and forced, or it
>>>>>>>> will go around.
>>>>>>>>
>>>>>>>> The limiting case, more and more denser and thinner fins,
>>>>>>>> volumetric air flow will approach zero.
>>>>>>>>
>>>>>>>> My general rule is that a heat sink should reduce the native air
>>>>>>>> flow by about half. Neither zero nor 100% does any cooling.
>>>>>>>
>>>>>>> And of course, the tips of tall thin fins have a high thermal
>>>>>>> resistance to the baseplate, so run at about inlet air temp, so
>>>>>>> restrict air flow without contributing much coolong. My 50% number
>>>>>>> is useless if the air flow is restricted without corresponding
>>>>>>> cooling.
>>>>>>>
>>>>>>> There is no limit to how bad a heat sink you can design. A solid
>>>>>>> aluminum brick is pretty bad.
>>>>>>
>>>>>> This works great:
>>>>>> http://panteltje.com/pub/big_3kg_heatsink_IMG_3745.GIF
>>>>>>
>>>>>> BTW that is a rubidum reference on top of it.
>>>>>>
>>>>>
>>>>> That is a very poor heat sink. Essentialy it conduction cools the
>>>>> device it is mounted to, but not much gets radiated away. More like
>>>>> a homogenizer.
>>>>>
>>>>> There is a reason that motorcycle air cooled cylinder jugs and
>>>>> heads are NOT painted.
>>>>
>>>> Radiation cooling goes as the 4th power of the temp difference between
>>>> the sink and the universe. Since semiconductors can't be allowed to
>>>> get very hot above ambient, rad cooling is usually minor. Inside a
>>>> metal box, a lot of the radiation is trapped and reflects back.
>>>
>>> The emission from a black body goes like T**4, so the thermal coupling
>>> between two surfaces goes like the difference, i.e. T1**4 - T2**4. For
>>> small temperature differences, that's basically 4 * T**3 * delta T.
>>>
>>> Cheers
>>>
>>> Phil Hobbs
>>
>> I wrote a little PowerBasic program to do the calc.
>>
>> https://www.dropbox.com/s/6a70p72e9yltsj7/Radcool2.EXE?dl=0
>>
>> It uses the equation from Reference Data for Radio Engineers.
>>
>> It's still pretty small for semiconductors on heat sinks.
>
>For two black bodies at 300K, the thermal impedance of radiation is
>about the same as 6 mm of air.
>
>Cheers
>
>Phil Hobbs

That's a fun number. That's a lot of thermal resistance, and the
insides of a metal box won't be a black body so things are worse in
real life.

--

I yam what I yam - Popeye

jlarkin@highlandsniptechnology.com wrote:
> On Sun, 17 Apr 2022 21:24:40 -0400, Phil Hobbs
> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>
>> jlarkin@highlandsniptechnology.com wrote:
>>> On Sun, 17 Apr 2022 16:49:40 -0400, Phil Hobbs
>>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>>>
>>>> jlarkin@highlandsniptechnology.com wrote:
>>>>> On Sun, 17 Apr 2022 17:50:59 -0000 (UTC),
>>>>> DecadentLinuxUserNumeroUno@decadence.org wrote:
>>>>>
>>>>>> Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote in
>>>>>> news:t3hijn$cus$1@dont-email.me:
>>>>>>
>>>>>>> On a sunny day (Sun, 17 Apr 2022 09:25:41 -0700) it happened
>>>>>>> jlarkin@highlandsniptechnology.com wrote in
>>>>>>> <thfo5ht952906bo9837snjolpjfd2lsc00@4ax.com>:
>>>>>>>
>>>>>>>> On Sun, 17 Apr 2022 09:10:41 -0700,
>>>>>>>> jlarkin@highlandsniptechnology.com wrote:
>>>>>>>>
>>>>>>>>> On Sun, 17 Apr 2022 15:55:21 -0000 (UTC),
>>>>>>>>> DecadentLinuxUserNumeroUno@decadence.org wrote:
>>>>>>>>>
>>>>>>>>>> Ricky <gnuarm.deletethisbit@gmail.com> wrote in
>>>>>>>>>> news:3f3e0e0f-175e-4d27-be95-401418cc7e54n@googlegroups.com:
>>>>>>>>>>
>>>>>>>>>>> The large surface area of the long, skinny fins are perfect
>>>>>>>>>>> coupling between the low thermal resistance of the heat sink
>>>>>>>>>>> and the relatively high thermal conductivity of the fin/air
>>>>>>>>>>> contact.
>>>>>>>>>>
>>>>>>>>>> The word(s) for today is "boundary layer".
>>>>>>>>>>
>>>>>>>>>> <https://www.heatsinkcalculator.com/blog/wp-
>>>>>>>>>> content/uploads/2016/05/effect_of_boundary_laher_thickness.png>
>>>>>>>>>>
>>>>>>>>>> <https://www.heatsinkcalculator.com/blog/top-3-mistakes-made-when
>>>>>>>>>> - selecting-a-heat-sink/>
>>>>>>>>>>
>>>>>>>>>> Slow air would pass right over a close fin spaced sink. High
>>>>>>>>>> speed
>>>>>>>>>> forced air is required when the fins get that closely spaced.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Right. Viscous drag will keep air from flowing between tall,
>>>>>>>>> closely spaced fins. It will have to be ducted and forced, or it
>>>>>>>>> will go around.
>>>>>>>>>
>>>>>>>>> The limiting case, more and more denser and thinner fins,
>>>>>>>>> volumetric air flow will approach zero.
>>>>>>>>>
>>>>>>>>> My general rule is that a heat sink should reduce the native air
>>>>>>>>> flow by about half. Neither zero nor 100% does any cooling.
>>>>>>>>
>>>>>>>> And of course, the tips of tall thin fins have a high thermal
>>>>>>>> resistance to the baseplate, so run at about inlet air temp, so
>>>>>>>> restrict air flow without contributing much coolong. My 50% number
>>>>>>>> is useless if the air flow is restricted without corresponding
>>>>>>>> cooling.
>>>>>>>>
>>>>>>>> There is no limit to how bad a heat sink you can design. A solid
>>>>>>>> aluminum brick is pretty bad.
>>>>>>>
>>>>>>> This works great:
>>>>>>> http://panteltje.com/pub/big_3kg_heatsink_IMG_3745.GIF
>>>>>>>
>>>>>>> BTW that is a rubidum reference on top of it.
>>>>>>>
>>>>>>
>>>>>> That is a very poor heat sink. Essentialy it conduction cools the
>>>>>> device it is mounted to, but not much gets radiated away. More like
>>>>>> a homogenizer.
>>>>>>
>>>>>> There is a reason that motorcycle air cooled cylinder jugs and
>>>>>> heads are NOT painted.
>>>>>
>>>>> Radiation cooling goes as the 4th power of the temp difference between
>>>>> the sink and the universe. Since semiconductors can't be allowed to
>>>>> get very hot above ambient, rad cooling is usually minor. Inside a
>>>>> metal box, a lot of the radiation is trapped and reflects back.
>>>>
>>>> The emission from a black body goes like T**4, so the thermal coupling
>>>> between two surfaces goes like the difference, i.e. T1**4 - T2**4. For
>>>> small temperature differences, that's basically 4 * T**3 * delta T.
>>>>
>>>> Cheers
>>>>
>>>> Phil Hobbs
>>>
>>> I wrote a little PowerBasic program to do the calc.
>>>
>>> https://www.dropbox.com/s/6a70p72e9yltsj7/Radcool2.EXE?dl=0
>>>
>>> It uses the equation from Reference Data for Radio Engineers.
>>>
>>> It's still pretty small for semiconductors on heat sinks.
>>
>> For two black bodies at 300K, the thermal impedance of radiation is
>> about the same as 6 mm of air.
>>
>
> That's a fun number. That's a lot of thermal resistance, and the
> insides of a metal box won't be a black body so things are worse in
> real life.

Until convection gets going, right. That's also the reason that foam
and fibre-batt insulation isn't just immobilized air, as is often
said--you need to scatter the IR radiation every few millimetres at most.

Photon budgets are a lot easier to do when you have a bag full of
fun-fact numbers like that: spheres scatter light into 4 pi steradians;
if your feedback resistor drops more than 50 mV, you're in the shot
noise limit; and so on and so forth.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Mon, 18 Apr 2022 10:17:21 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>jlarkin@highlandsniptechnology.com wrote:
>> On Sun, 17 Apr 2022 21:24:40 -0400, Phil Hobbs
>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>>
>>> jlarkin@highlandsniptechnology.com wrote:
>>>> On Sun, 17 Apr 2022 16:49:40 -0400, Phil Hobbs
>>>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>>>>
>>>>> jlarkin@highlandsniptechnology.com wrote:
>>>>>> On Sun, 17 Apr 2022 17:50:59 -0000 (UTC),
>>>>>> DecadentLinuxUserNumeroUno@decadence.org wrote:
>>>>>>
>>>>>>> Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote in
>>>>>>> news:t3hijn$cus$1@dont-email.me:
>>>>>>>
>>>>>>>> On a sunny day (Sun, 17 Apr 2022 09:25:41 -0700) it happened
>>>>>>>> jlarkin@highlandsniptechnology.com wrote in
>>>>>>>> <thfo5ht952906bo9837snjolpjfd2lsc00@4ax.com>:
>>>>>>>>
>>>>>>>>> On Sun, 17 Apr 2022 09:10:41 -0700,
>>>>>>>>> jlarkin@highlandsniptechnology.com wrote:
>>>>>>>>>
>>>>>>>>>> On Sun, 17 Apr 2022 15:55:21 -0000 (UTC),
>>>>>>>>>> DecadentLinuxUserNumeroUno@decadence.org wrote:
>>>>>>>>>>
>>>>>>>>>>> Ricky <gnuarm.deletethisbit@gmail.com> wrote in
>>>>>>>>>>> news:3f3e0e0f-175e-4d27-be95-401418cc7e54n@googlegroups.com:
>>>>>>>>>>>
>>>>>>>>>>>> The large surface area of the long, skinny fins are perfect
>>>>>>>>>>>> coupling between the low thermal resistance of the heat sink
>>>>>>>>>>>> and the relatively high thermal conductivity of the fin/air
>>>>>>>>>>>> contact.
>>>>>>>>>>>
>>>>>>>>>>> The word(s) for today is "boundary layer".
>>>>>>>>>>>
>>>>>>>>>>> <https://www.heatsinkcalculator.com/blog/wp-
>>>>>>>>>>> content/uploads/2016/05/effect_of_boundary_laher_thickness.png>
>>>>>>>>>>>
>>>>>>>>>>> <https://www.heatsinkcalculator.com/blog/top-3-mistakes-made-when
>>>>>>>>>>> - selecting-a-heat-sink/>
>>>>>>>>>>>
>>>>>>>>>>> Slow air would pass right over a close fin spaced sink. High
>>>>>>>>>>> speed
>>>>>>>>>>> forced air is required when the fins get that closely spaced.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Right. Viscous drag will keep air from flowing between tall,
>>>>>>>>>> closely spaced fins. It will have to be ducted and forced, or it
>>>>>>>>>> will go around.
>>>>>>>>>>
>>>>>>>>>> The limiting case, more and more denser and thinner fins,
>>>>>>>>>> volumetric air flow will approach zero.
>>>>>>>>>>
>>>>>>>>>> My general rule is that a heat sink should reduce the native air
>>>>>>>>>> flow by about half. Neither zero nor 100% does any cooling.
>>>>>>>>>
>>>>>>>>> And of course, the tips of tall thin fins have a high thermal
>>>>>>>>> resistance to the baseplate, so run at about inlet air temp, so
>>>>>>>>> restrict air flow without contributing much coolong. My 50% number
>>>>>>>>> is useless if the air flow is restricted without corresponding
>>>>>>>>> cooling.
>>>>>>>>>
>>>>>>>>> There is no limit to how bad a heat sink you can design. A solid
>>>>>>>>> aluminum brick is pretty bad.
>>>>>>>>
>>>>>>>> This works great:
>>>>>>>> http://panteltje.com/pub/big_3kg_heatsink_IMG_3745.GIF
>>>>>>>>
>>>>>>>> BTW that is a rubidum reference on top of it.
>>>>>>>>
>>>>>>>
>>>>>>> That is a very poor heat sink. Essentialy it conduction cools the
>>>>>>> device it is mounted to, but not much gets radiated away. More like
>>>>>>> a homogenizer.
>>>>>>>
>>>>>>> There is a reason that motorcycle air cooled cylinder jugs and
>>>>>>> heads are NOT painted.
>>>>>>
>>>>>> Radiation cooling goes as the 4th power of the temp difference between
>>>>>> the sink and the universe. Since semiconductors can't be allowed to
>>>>>> get very hot above ambient, rad cooling is usually minor. Inside a
>>>>>> metal box, a lot of the radiation is trapped and reflects back.
>>>>>
>>>>> The emission from a black body goes like T**4, so the thermal coupling
>>>>> between two surfaces goes like the difference, i.e. T1**4 - T2**4. For
>>>>> small temperature differences, that's basically 4 * T**3 * delta T.
>>>>>
>>>>> Cheers
>>>>>
>>>>> Phil Hobbs
>>>>
>>>> I wrote a little PowerBasic program to do the calc.
>>>>
>>>> https://www.dropbox.com/s/6a70p72e9yltsj7/Radcool2.EXE?dl=0
>>>>
>>>> It uses the equation from Reference Data for Radio Engineers.
>>>>
>>>> It's still pretty small for semiconductors on heat sinks.
>>>
>>> For two black bodies at 300K, the thermal impedance of radiation is
>>> about the same as 6 mm of air.
>>>
>>
>> That's a fun number. That's a lot of thermal resistance, and the
>> insides of a metal box won't be a black body so things are worse in
>> real life.
>
>Until convection gets going, right. That's also the reason that foam
>and fibre-batt insulation isn't just immobilized air, as is often
>said--you need to scatter the IR radiation every few millimetres at most.
>
>Photon budgets are a lot easier to do when you have a bag full of
>fun-fact numbers like that: spheres scatter light into 4 pi steradians;
>if your feedback resistor drops more than 50 mV, you're in the shot
>noise limit; and so on and so forth.
>
>Cheers
>
>Phil Hobbs

I experimented with covers over heated blocks, namely with various
types of insulation. Given a pretty close fitting cover, the best
insulation is none.

https://www.dropbox.com/s/9v4dse1vv4vjs0w/P500_XO_Cover.jpg?raw=1

--

I yam what I yam - Popeye

On 2022-04-17 16:49, jlarkin@highlandsniptechnology.com wrote:
> On Sun, 17 Apr 2022 12:31:52 +0200, "Carlos E.R."
> <robin_listas@es.invalid> wrote:
>
>> On 2022-04-17 00:23, jlarkin@highlandsniptechnology.com wrote:
>>> On Sat, 16 Apr 2022 19:51:56 -0000 (UTC), Cydrome Leader
>>> <presence@MUNGEpanix.com> wrote:
>>>
>>>> bitrex <user@example.net> wrote:
>>>>> I thought they were extruded, but no!
>>>>>
>>>>> <https://youtu.be/wwWIyHo3yJM>
>>>>>
>>>>> Like carving a turkey dinner
>>>>
>>>> Skiving is real slow. The only value is you get thinner fins than can be
>>>> extruded. More machining is needed if you want holes though any of that.
>>>
>>> Those long skinny fins don't look efficient to me. And they would need
>>> a huge air blast.
>>
>> I don't think so: a strong air blast would bend the fins.
>
> That strong would destroy the enclosure and kill bystanders.

I don't think so, those fins are almost paper thin.

--
Cheers, Carlos.

On Fri, 15 Apr 2022 23:58:13 +0100, bitrex <user@example.net> wrote:

> I thought they were extruded, but no!
>
> <https://youtu.be/wwWIyHo3yJM>
>
> Like carving a turkey dinner

How does that even work? The bit at the end of each one where it magically bends up to the vertical.

On Sun, 17 Apr 2022 01:10:31 +0100, Ricky <gnuarm.deletethisbit@gmail.com> wrote:

> On Saturday, April 16, 2022 at 6:23:26 PM UTC-4, jla...@highlandsniptechnology.com wrote:
>> On Sat, 16 Apr 2022 19:51:56 -0000 (UTC), Cydrome Leader
>> <pres...@MUNGEpanix.com> wrote:
>>
>> >bitrex <us...@example.net> wrote:
>> >> I thought they were extruded, but no!
>> >>
>> >> <https://youtu.be/wwWIyHo3yJM>
>> >>
>> >> Like carving a turkey dinner
>> >
>> >Skiving is real slow. The only value is you get thinner fins than can be
>> >extruded. More machining is needed if you want holes though any of that.
>> Those long skinny fins don't look efficient to me. And they would need
>> a huge air blast.
>
> Does anyone know what he is talking about?
>
> The large surface area of the long, skinny fins are perfect coupling between the low thermal resistance of the heat sink and the relatively high thermal conductivity of the fin/air contact. Lots of surface area gives a low thermal resistance at the point of contact. That's the point of using them.
>
> It's the extruded heat sinks with much fewer fins

Oooooh fewer eh?

On Mon, 18 Apr 2022 22:42:17 +0100, Carlos E.R. <robin_listas@es.invalid> wrote:

> On 2022-04-17 16:49, jlarkin@highlandsniptechnology.com wrote:
>> On Sun, 17 Apr 2022 12:31:52 +0200, "Carlos E.R."
>> <robin_listas@es.invalid> wrote:
>>
>>> On 2022-04-17 00:23, jlarkin@highlandsniptechnology.com wrote:
>>>> On Sat, 16 Apr 2022 19:51:56 -0000 (UTC), Cydrome Leader
>>>> <presence@MUNGEpanix.com> wrote:
>>>>
>>>>> bitrex <user@example.net> wrote:
>>>>>> I thought they were extruded, but no!
>>>>>>
>>>>>> <https://youtu.be/wwWIyHo3yJM>
>>>>>>
>>>>>> Like carving a turkey dinner
>>>>>
>>>>> Skiving is real slow. The only value is you get thinner fins than can be
>>>>> extruded. More machining is needed if you want holes though any of that.
>>>>
>>>> Those long skinny fins don't look efficient to me. And they would need
>>>> a huge air blast.
>>>
>>> I don't think so: a strong air blast would bend the fins.
>>
>> That strong would destroy the enclosure and kill bystanders.
>
> I don't think so, those fins are almost paper thin.

So they'd be almost destroyed.

On Sat, 16 Apr 2022 22:05:25 +0100, Ricky <gnuarm.deletethisbit@gmail.com> wrote:

> On Friday, April 15, 2022 at 6:58:20 PM UTC-4, bitrex wrote:
>> I thought they were extruded, but no!
>>
>> <https://youtu.be/wwWIyHo3yJM>
>>
>> Like carving a turkey dinner
>
> This gets you more fins for better transfer to the air. People focus on silly points like diamond heat sink grease, when they often lose far more performance at other points in the heat path. Ultimately there is a limit on how larger a heat sink you can attach to a CPU/GPU directly.

I have a 6 inch cube attached to mine.

> If size and cost are not an issue, heat pipes to connect the heat block on the CPU/GPU to a much larger thermal air interface. Bigger fins, bigger fan and much better performance.
>
> Then water cooling can get even better performance, and the noisy bits can be somewhere else, even in another room. I remember discussing this with a guy who ran the tubes to a drum in his garage where he didn't even need to use an air interface. The thermal mass of the drum was good enough to absorb the heat for the time he ran the computer. Zero noise other than the power supply fan, I suppose he still had one of those.

Water cooling manufacturers have lost the plot, they move the water to a heatsink wtih.... fans! The one I had years ago had a huge water tower which cooled by convection. There's no point in water cooling if you still have fans!

On Monday, April 18, 2022 at 5:44:12 PM UTC-4, Carlos E.R. wrote:
> On 2022-04-17 16:49, jla...@highlandsniptechnology.com wrote:
> > On Sun, 17 Apr 2022 12:31:52 +0200, "Carlos E.R."
> > <robin_...@es.invalid> wrote:
> >
> >> On 2022-04-17 00:23, jla...@highlandsniptechnology.com wrote:
> >>> On Sat, 16 Apr 2022 19:51:56 -0000 (UTC), Cydrome Leader
> >>> <pres...@MUNGEpanix.com> wrote:
> >>>
> >>>> bitrex <us...@example.net> wrote:
> >>>>> I thought they were extruded, but no!
> >>>>>
> >>>>> <https://youtu.be/wwWIyHo3yJM>
> >>>>>
> >>>>> Like carving a turkey dinner
> >>>>
> >>>> Skiving is real slow. The only value is you get thinner fins than can be
> >>>> extruded. More machining is needed if you want holes though any of that.
> >>>
> >>> Those long skinny fins don't look efficient to me. And they would need
> >>> a huge air blast.
> >>
> >> I don't think so: a strong air blast would bend the fins.
> >
> > That strong would destroy the enclosure and kill bystanders.
>
> I don't think so, those fins are almost paper thin.

You mean like aluminum foil? They don't look that thin. They seem to stand up to the blade well when it pushes them straight up. More like card stock, which in aluminum, is not all that flexible. The metal used in radiators was very thin. It stood up to a bit of abuse because it was metal. Now they use plastic, which amazed me they could get to work well!

I think you are being a bit disingenuous.

--

Rick C.

-+- Get 1,000 miles of free Supercharging
-+- Tesla referral code - https://ts.la/richard11209

On Monday, April 18, 2022 at 5:54:03 PM UTC-4, Commander Kinsey wrote:
> On Sat, 16 Apr 2022 22:05:25 +0100, Ricky <gnuarm.del...@gmail.com> wrote:
> > On Friday, April 15, 2022 at 6:58:20 PM UTC-4, bitrex wrote:
> >> I thought they were extruded, but no!
> >>
> >> <https://youtu.be/wwWIyHo3yJM>
> >>
> >> Like carving a turkey dinner
> >
> > This gets you more fins for better transfer to the air. People focus on silly points like diamond heat sink grease, when they often lose far more performance at other points in the heat path. Ultimately there is a limit on how larger a heat sink you can attach to a CPU/GPU directly.
>
> I have a 6 inch cube attached to mine.
>
> > If size and cost are not an issue, heat pipes to connect the heat block on the CPU/GPU to a much larger thermal air interface. Bigger fins, bigger fan and much better performance.
> >
> > Then water cooling can get even better performance, and the noisy bits can be somewhere else, even in another room. I remember discussing this with a guy who ran the tubes to a drum in his garage where he didn't even need to use an air interface. The thermal mass of the drum was good enough to absorb the heat for the time he ran the computer. Zero noise other than the power supply fan, I suppose he still had one of those.
>
> Water cooling manufacturers have lost the plot, they move the water to a heatsink wtih.... fans! The one I had years ago had a huge water tower which cooled by convection. There's no point in water cooling if you still have fans!

Lol! You are so funny sometimes. You remind me of DLUNU. Unable to even understand what you've read.

--

Rick C.

-++ Get 1,000 miles of free Supercharging
-++ Tesla referral code - https://ts.la/richard11209

On Mon, 18 Apr 2022 23:00:34 +0100, Ricky <gnuarm.deletethisbit@gmail.com> wrote:

> On Monday, April 18, 2022 at 5:54:03 PM UTC-4, Commander Kinsey wrote:
>> On Sat, 16 Apr 2022 22:05:25 +0100, Ricky <gnuarm.del...@gmail.com> wrote:
>> > On Friday, April 15, 2022 at 6:58:20 PM UTC-4, bitrex wrote:
>> >> I thought they were extruded, but no!
>> >>
>> >> <https://youtu.be/wwWIyHo3yJM>
>> >>
>> >> Like carving a turkey dinner
>> >
>> > This gets you more fins for better transfer to the air. People focus on silly points like diamond heat sink grease, when they often lose far more performance at other points in the heat path. Ultimately there is a limit on how larger a heat sink you can attach to a CPU/GPU directly.
>>
>> I have a 6 inch cube attached to mine.
>>
>> > If size and cost are not an issue, heat pipes to connect the heat block on the CPU/GPU to a much larger thermal air interface. Bigger fins, bigger fan and much better performance.
>> >
>> > Then water cooling can get even better performance, and the noisy bits can be somewhere else, even in another room. I remember discussing this with a guy who ran the tubes to a drum in his garage where he didn't even need to use an air interface. The thermal mass of the drum was good enough to absorb the heat for the time he ran the computer. Zero noise other than the power supply fan, I suppose he still had one of those.
>>
>> Water cooling manufacturers have lost the plot, they move the water to a heatsink wtih.... fans! The one I had years ago had a huge water tower which cooled by convection. There's no point in water cooling if you still have fans!
>
> Lol! You are so funny sometimes. You remind me of DLUNU. Unable to even understand what you've read.

You're not right in the head, let me make it simple for you:

This is a typical water cooling arrangement: https://www.bhphotovideo.com/images/images2500x2500/corsair_cw_9060014_ww_hydro_series_h110_280mm_1094578.jpg

Notice how the fans will be only a foot away from where they would be anyway. So utterly pointless. All they've done is introduce another point of failure, the pump. Oh and the leaks.

So er... what was I read wrong?

On Monday, April 18, 2022 at 5:51:16 PM UTC-4, Commander Kinsey wrote:
> On Fri, 15 Apr 2022 23:58:13 +0100, bitrex <us...@example.net> wrote:
>
> > I thought they were extruded, but no!
> >
> > <https://youtu.be/wwWIyHo3yJM>
> >
> > Like carving a turkey dinner
> How does that even work? The bit at the end of each one where it magically bends up to the vertical.

Yeah... "How dem do dat?"

Last of the great thinkers. You saw the video. What do you think?

--

Rick C.

+-- Get 1,000 miles of free Supercharging
+-- Tesla referral code - https://ts.la/richard11209

On Monday, April 18, 2022 at 6:20:25 PM UTC-4, Commander Kinsey wrote:
> On Mon, 18 Apr 2022 23:00:34 +0100, Ricky <gnuarm.del...@gmail.com> wrote:
>
> > On Monday, April 18, 2022 at 5:54:03 PM UTC-4, Commander Kinsey wrote:
> >> On Sat, 16 Apr 2022 22:05:25 +0100, Ricky <gnuarm.del...@gmail.com> wrote:
> >> > On Friday, April 15, 2022 at 6:58:20 PM UTC-4, bitrex wrote:
> >> >> I thought they were extruded, but no!
> >> >>
> >> >> <https://youtu.be/wwWIyHo3yJM>
> >> >>
> >> >> Like carving a turkey dinner
> >> >
> >> > This gets you more fins for better transfer to the air. People focus on silly points like diamond heat sink grease, when they often lose far more performance at other points in the heat path. Ultimately there is a limit on how larger a heat sink you can attach to a CPU/GPU directly.
> >>
> >> I have a 6 inch cube attached to mine.
> >>
> >> > If size and cost are not an issue, heat pipes to connect the heat block on the CPU/GPU to a much larger thermal air interface. Bigger fins, bigger fan and much better performance.
> >> >
> >> > Then water cooling can get even better performance, and the noisy bits can be somewhere else, even in another room. I remember discussing this with a guy who ran the tubes to a drum in his garage where he didn't even need to use an air interface. The thermal mass of the drum was good enough to absorb the heat for the time he ran the computer. Zero noise other than the power supply fan, I suppose he still had one of those.
> >>
> >> Water cooling manufacturers have lost the plot, they move the water to a heatsink wtih.... fans! The one I had years ago had a huge water tower which cooled by convection. There's no point in water cooling if you still have fans!
> >
> > Lol! You are so funny sometimes. You remind me of DLUNU. Unable to even understand what you've read.
> You're not right in the head, let me make it simple for you:
>
> This is a typical water cooling arrangement: https://www.bhphotovideo.com/images/images2500x2500/corsair_cw_9060014_ww_hydro_series_h110_280mm_1094578.jpg
>
> Notice how the fans will be only a foot away from where they would be anyway. So utterly pointless. All they've done is introduce another point of failure, the pump. Oh and the leaks.
>
> So er... what was I read wrong?

I don't know what you read wrong. What did you read? Maybe nothing.

--

Rick C.

+-+ Get 1,000 miles of free Supercharging
+-+ Tesla referral code - https://ts.la/richard11209

On Mon, 18 Apr 2022 23:42:17 +0200, "Carlos E.R."
<robin_listas@es.invalid> wrote:

>On 2022-04-17 16:49, jlarkin@highlandsniptechnology.com wrote:
>> On Sun, 17 Apr 2022 12:31:52 +0200, "Carlos E.R."
>> <robin_listas@es.invalid> wrote:
>>
>>> On 2022-04-17 00:23, jlarkin@highlandsniptechnology.com wrote:
>>>> On Sat, 16 Apr 2022 19:51:56 -0000 (UTC), Cydrome Leader
>>>> <presence@MUNGEpanix.com> wrote:
>>>>
>>>>> bitrex <user@example.net> wrote:
>>>>>> I thought they were extruded, but no!
>>>>>>
>>>>>> <https://youtu.be/wwWIyHo3yJM>
>>>>>>
>>>>>> Like carving a turkey dinner
>>>>>
>>>>> Skiving is real slow. The only value is you get thinner fins than can be
>>>>> extruded. More machining is needed if you want holes though any of that.
>>>>
>>>> Those long skinny fins don't look efficient to me. And they would need
>>>> a huge air blast.
>>>
>>> I don't think so: a strong air blast would bend the fins.
>>
>> That strong would destroy the enclosure and kill bystanders.
>
>I don't think so, those fins are almost paper thin.

I have a skived copper heat sink, the one I posted a pic of. It got
bashed some and some fins got bent. It took some muscle and pliers to
straighten them out.

Get one. Blow some air on it and see if the fins bend.

The skived fins on a copper CPU cooler seem to be about 10 to 15 mils
thick. Look to be some copper alloy, harder than pure copper. Pure
copper and aluminum are both nasty to machine, and the alloys fix that
but wreck the thermal and electrical conductivity.

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

On Mon, 18 Apr 2022 22:52:28 +0100, "Commander Kinsey"
<CK1@nospam.com> wrote:

>On Mon, 18 Apr 2022 22:42:17 +0100, Carlos E.R. <robin_listas@es.invalid> wrote:
>
>> On 2022-04-17 16:49, jlarkin@highlandsniptechnology.com wrote:
>>> On Sun, 17 Apr 2022 12:31:52 +0200, "Carlos E.R."
>>> <robin_listas@es.invalid> wrote:
>>>
>>>> On 2022-04-17 00:23, jlarkin@highlandsniptechnology.com wrote:
>>>>> On Sat, 16 Apr 2022 19:51:56 -0000 (UTC), Cydrome Leader
>>>>> <presence@MUNGEpanix.com> wrote:
>>>>>
>>>>>> bitrex <user@example.net> wrote:
>>>>>>> I thought they were extruded, but no!
>>>>>>>
>>>>>>> <https://youtu.be/wwWIyHo3yJM>
>>>>>>>
>>>>>>> Like carving a turkey dinner
>>>>>>
>>>>>> Skiving is real slow. The only value is you get thinner fins than can be
>>>>>> extruded. More machining is needed if you want holes though any of that.
>>>>>
>>>>> Those long skinny fins don't look efficient to me. And they would need
>>>>> a huge air blast.
>>>>
>>>> I don't think so: a strong air blast would bend the fins.
>>>
>>> That strong would destroy the enclosure and kill bystanders.
>>
>> I don't think so, those fins are almost paper thin.
>
>So they'd be almost destroyed.

There are data sheets for heat sinks. I suspect they include
dimensions. You know, numbers.

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

On Mon, 18 Apr 2022 23:50:48 +0100, John Larkin <jlarkin@highland_atwork_technology.com> wrote:

> On Mon, 18 Apr 2022 22:52:28 +0100, "Commander Kinsey"
> <CK1@nospam.com> wrote:
>
>> On Mon, 18 Apr 2022 22:42:17 +0100, Carlos E.R. <robin_listas@es.invalid> wrote:
>>
>>> On 2022-04-17 16:49, jlarkin@highlandsniptechnology.com wrote:
>>>> On Sun, 17 Apr 2022 12:31:52 +0200, "Carlos E.R."
>>>> <robin_listas@es.invalid> wrote:
>>>>
>>>>> On 2022-04-17 00:23, jlarkin@highlandsniptechnology.com wrote:
>>>>>> On Sat, 16 Apr 2022 19:51:56 -0000 (UTC), Cydrome Leader
>>>>>> <presence@MUNGEpanix.com> wrote:
>>>>>>
>>>>>>> bitrex <user@example.net> wrote:
>>>>>>>> I thought they were extruded, but no!
>>>>>>>>
>>>>>>>> <https://youtu.be/wwWIyHo3yJM>
>>>>>>>>
>>>>>>>> Like carving a turkey dinner
>>>>>>>
>>>>>>> Skiving is real slow. The only value is you get thinner fins than can be
>>>>>>> extruded. More machining is needed if you want holes though any of that.
>>>>>>
>>>>>> Those long skinny fins don't look efficient to me. And they would need
>>>>>> a huge air blast.
>>>>>
>>>>> I don't think so: a strong air blast would bend the fins.
>>>>
>>>> That strong would destroy the enclosure and kill bystanders.
>>>
>>> I don't think so, those fins are almost paper thin.
>>
>> So they'd be almost destroyed.
>
> There are data sheets for heat sinks. I suspect they include
> dimensions. You know, numbers.

Since you know so much about them, why does mine have some copper fins and some aluminium? Surely either one or the other is better? Or is it just to make it look pretty?

On Mon, 18 Apr 2022 22:53:54 +0100, "Commander Kinsey"
<CK1@nospam.com> wrote:

>On Sat, 16 Apr 2022 22:05:25 +0100, Ricky <gnuarm.deletethisbit@gmail.com> wrote:
>
>> On Friday, April 15, 2022 at 6:58:20 PM UTC-4, bitrex wrote:
>>> I thought they were extruded, but no!
>>>
>>> <https://youtu.be/wwWIyHo3yJM>
>>>
>>> Like carving a turkey dinner
>>
>> This gets you more fins for better transfer to the air. People focus on silly points like diamond heat sink grease, when they often lose far more performance at other points in the heat path. Ultimately there is a limit on how larger a heat sink you can attach to a CPU/GPU directly.
>
>I have a 6 inch cube attached to mine.
>
>> If size and cost are not an issue, heat pipes to connect the heat block on the CPU/GPU to a much larger thermal air interface. Bigger fins, bigger fan and much better performance.
>>
>> Then water cooling can get even better performance, and the noisy bits can be somewhere else, even in another room. I remember discussing this with a guy who ran the tubes to a drum in his garage where he didn't even need to use an air interface. The thermal mass of the drum was good enough to absorb the heat for the time he ran the computer. Zero noise other than the power supply fan, I suppose he still had one of those.
>
>Water cooling manufacturers have lost the plot, they move the water to a heatsink wtih.... fans! The one I had years ago had a huge water tower which cooled by convection. There's no point in water cooling if you still have fans!

Like a car? No point?

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

On Mon, 18 Apr 2022 23:41:56 +0100, Ricky <gnuarm.deletethisbit@gmail.com> wrote:

> On Monday, April 18, 2022 at 5:51:16 PM UTC-4, Commander Kinsey wrote:
>> On Fri, 15 Apr 2022 23:58:13 +0100, bitrex <us...@example.net> wrote:
>>
>> > I thought they were extruded, but no!
>> >
>> > <https://youtu.be/wwWIyHo3yJM>
>> >
>> > Like carving a turkey dinner
>> How does that even work? The bit at the end of each one where it magically bends up to the vertical.
>
> Yeah... "How dem do dat?"
>
> Last of the great thinkers. You saw the video. What do you think?

I have no idea, which is why I asked, duh.

On Mon, 18 Apr 2022 23:44:00 +0100, Ricky <gnuarm.deletethisbit@gmail.com> wrote:

> On Monday, April 18, 2022 at 6:20:25 PM UTC-4, Commander Kinsey wrote:
>> On Mon, 18 Apr 2022 23:00:34 +0100, Ricky <gnuarm.del...@gmail.com> wrote:
>>
>> > On Monday, April 18, 2022 at 5:54:03 PM UTC-4, Commander Kinsey wrote:
>> >> On Sat, 16 Apr 2022 22:05:25 +0100, Ricky <gnuarm.del...@gmail.com> wrote:
>> >> > On Friday, April 15, 2022 at 6:58:20 PM UTC-4, bitrex wrote:
>> >> >> I thought they were extruded, but no!
>> >> >>
>> >> >> <https://youtu.be/wwWIyHo3yJM>
>> >> >>
>> >> >> Like carving a turkey dinner
>> >> >
>> >> > This gets you more fins for better transfer to the air. People focus on silly points like diamond heat sink grease, when they often lose far more performance at other points in the heat path. Ultimately there is a limit on how larger a heat sink you can attach to a CPU/GPU directly.
>> >>
>> >> I have a 6 inch cube attached to mine.
>> >>
>> >> > If size and cost are not an issue, heat pipes to connect the heat block on the CPU/GPU to a much larger thermal air interface. Bigger fins, bigger fan and much better performance.
>> >> >
>> >> > Then water cooling can get even better performance, and the noisy bits can be somewhere else, even in another room. I remember discussing this with a guy who ran the tubes to a drum in his garage where he didn't even need to use an air interface. The thermal mass of the drum was good enough to absorb the heat for the time he ran the computer. Zero noise other than the power supply fan, I suppose he still had one of those.
>> >>
>> >> Water cooling manufacturers have lost the plot, they move the water to a heatsink wtih.... fans! The one I had years ago had a huge water tower which cooled by convection. There's no point in water cooling if you still have fans!
>> >
>> > Lol! You are so funny sometimes. You remind me of DLUNU. Unable to even understand what you've read.
>> You're not right in the head, let me make it simple for you:
>>
>> This is a typical water cooling arrangement: https://www.bhphotovideo.com/images/images2500x2500/corsair_cw_9060014_ww_hydro_series_h110_280mm_1094578.jpg
>>
>> Notice how the fans will be only a foot away from where they would be anyway. So utterly pointless. All they've done is introduce another point of failure, the pump. Oh and the leaks.
>>
>> So er... what was I read wrong?
>
> I don't know what you read wrong. What did you read? Maybe nothing.

You wrote nothing to explain the point of the image I just showed you.