# Aluminum vs Copper cooling



## freaksavior (Sep 26, 2007)

So I have noticed over the past year, that there are many questions regarding what's a better material for cpu cooling.

Aluminum has a specific heat of 0.9000 J over G x C

Copper has a specific heat of 0.3851 J over G x C 

So copper will heat up more quickly than aluminum. I would go into the process of the equation but i don't quite know how to write it out. so hopefully that helped someone. if someone knows the equation for the specific heat and all that stuff, please share (btw it's chemistry)


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## freaksavior (Sep 26, 2007)

sorry for double post, but does anybody know a cpu cooler that is made in aluminum and then exactly the same in copper?


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## pt (Sep 26, 2007)

freaksavior said:


> sorry for double post, but does anybody know a cpu cooler that is made in aluminum and then exactly the same in copper?



the thermalright xp-90 has 2 variants


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## DaMulta (Sep 26, 2007)

a radiator will work better as Aluminum, because Aluminum will disperse heat better. Copper will absorb the heat better than Aluminum, but is not as good as dispersing  it.


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## gR3iF (Sep 26, 2007)

The point for this is air:
Air is the medium that will get the heat after getting it away from the cpu.


So to use a metall mix: Use a cooper plate on the cpu and then alu because alu or cooper give the same amount of heat to the air. It just cant take anymore.

To bring in something new: Heatpipes they can transport more heat than cooper. That is the reason for there usage nowadays and something like this:






All in all a mixup of heatpipes and cooper is the effective way for aircooling.
The only thing to use alu is the price and the thing that air absorbs the heat and this isnt affected by alu or cooper usage.


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## freaksavior (Sep 26, 2007)

hmm, so basically what your saying is, it is best to have a copper plate/base, then aluminum fins.


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## DaMulta (Sep 26, 2007)

freaksavior said:


> hmm, so basically what your saying is, it is best to have a copper plate/base, then aluminum fins.



Yes


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## gR3iF (Sep 26, 2007)

Yep that is right


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## freaksavior (Sep 26, 2007)

this is interesting to me.....i didn't know this lol


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## gR3iF (Sep 26, 2007)

Then use the thank button ;D

Its fact so far that Heatpipes are best for transporting heat. The negative point about them ist that they are hardly to work into a base plate or something normally u get then a profile like a rock so the contact area looks really ugly and then the advantage of using heatpipes is gone.

So normally Manufactures uses a flat cooper base plate and then heatpipes soldered to it and then fins out of alu or cooper (this makes the price)

Look at the Zalmann 9500-9700 series they are really good cooler and they work with this simple thing.


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## largon (Sep 26, 2007)

DaMulta said:


> a radiator will work better as Aluminum, because Aluminum will disperse heat better. Copper will absorb the heat better than Aluminum, but is not as good as dispersing  it.


Aluminium is inferior for it's thermal specs compared to copper. Alu _does not_ "disperse" heat better than copper. Infact, no such specific physical feature in different substances exists which dictates how well the material gives away heat. Matter can release heat by three methods: conduction, convection and radiation. Convection applies only to liquids and gases. 

The only things that matter for conduction and radiability are:
- thermal resistance
- surface area
- color

Aluminium is popular _only_ because it's cheaper than copper. 

Real world example: 
Thermalright XP-90 vs. XP-90c @ SystemCooling.com
->

XP-90 has a copper base and copper heatpipes with alu fins whereas XP-90c is all copper. 
Still, XP-90c wins hands down.


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## jtleon (Sep 26, 2007)

*How about a bit of Engineering Data.....*

You can see the thermal conductivity (the rate at which heat flows within a material) of copper and other materials here:

http://hypertextbook.com/physics/thermal/conduction/

Aluminum has conductivity value of 237 W/m.K (Watts/Meter x degrees Kelvin)

Copper has conductivity value of 401 W/m.K.

Air has conductivity of 0.025 W/m.K

The biggest engineering challenge is to force the energy to jump from the Aluminum or Copper to the Air.  As you can see, air has a very low energy conduction rate.  Gigantic amounts of exposed surface area to air are required to facilitate efficient transfer of energy from the metal to the air.  Air flow velocity also plays a critical role - more flow=more transfer.  

If the HS geometry is the same, then the Copper design should perform almost twice as well as the Aluminum design.

Note that:
Diamond has conductivity of 895 W/m.K

Carbon Graphite is the very best at 1950 W/m.K

Soon we will see HSF's with diamond or graphite components.  By the way, carbon graphite is already used in most brushes for electric motors, and pencil lead.  OCZ did have a carbon graphite demo heatsink at one time in the recent past.

Regards,
jtleon


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## theonetruewill (Sep 26, 2007)

largon said:


> Aluminium is inferior for it's thermal specs compared to copper. Alu _does not_ "disperse" heat better than copper. Infact, no such specific physical feature in different substances exists which dictates how well the material gives away heat. Matter can release heat by three methods: conduction, convection and radiation. Convection applies only to liquids and gases.
> 
> The only things that matter for conduction and radiability are:
> - thermal resistance
> ...


I agree, this info is correct. jtleon is also correct.


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## Oliver_FF (Sep 26, 2007)

theonetruewill said:


> Aluminium is popular only because it's cheaper than copper.



It's also popular because copper is way heavier than aluminium and doesn't corrode as easily. Sweaty hands on a pure copper heatsink will leave you with dark finger prints all over it, axeing it's usefulness...


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## a111087 (Sep 26, 2007)

pt said:


> the thermalright xp-90 has 2 variants



just wanted to tell you guys that i saw a review of both of these and copper of course won, but by ~3C or something like that


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## DaMulta (Sep 26, 2007)

http://www.chevellecooling.com/43.html


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## POGE (Sep 26, 2007)

Copper has all around better thermal properties, aluminum is just easier to work with sometimes, and is also a lot cheaper.


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## t_ski (Sep 26, 2007)

I read a recommendation a long time ago, so I can't remember the source offhand, that using different metals were better in different circumstances.  Specifically, using aluminum was better when the unit was to be cooled passively, but copper was better when cooled actively.  IIRC the difference was based on how the metal absorbed and dispersed the heat, and how the difference was when the airflow was changed around them.

By the way, there are other metals out there that are more conductive than copper, but obviously cost becomes a limiting factor.  Silver is one of those metals, and has been used to make a couple Danger Den blocks (among others): the TDX and the RBX.


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## panchoman (Sep 26, 2007)

jtleon said:


> You can see the thermal conductivity (the rate at which heat flows within a material) of copper and other materials here:
> 
> http://hypertextbook.com/physics/thermal/conduction/
> 
> ...



why didn't they make carbon graphite from the start? seems mad cheap considering its pencil lead.... and i agree with him. the most conductivity the material has, the faster it can move the heat away fromthe cpu.


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## jtleon (Sep 26, 2007)

*Some Clarification*



jtleon said:


> If the HS geometry is the same, then the Copper design should perform almost twice as well as the Aluminum design.



My statement above does not mean that the Copper model will be twice as cold as the Aluminum model - it will only dissipate about twice the energy, which in many cases results in only a few degrees cooler operation - considering all three transfer phenomena (conduction, convection, and radiation occurring simultaneously)

In other words, if both the copper and aluminum heatsinks were the same temperature, the energy input would be almost twice as great in the copper model.
Regards,
jtleon


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## jtleon (Sep 26, 2007)

*Carbon Graphite manufacturing is big money....*



panchoman said:


> why didn't they make carbon graphite from the start? seems mad cheap considering its pencil lead.... and i agree with him. the most conductivity the material has, the faster it can move the heat away fromthe cpu.



Note that carbon graphite in pencil lead is only a small percentage carbon graphite, the remainder is a polymer that binds the particles together.  In this form, the conductivity is very poor, given the low particle population.

After reviewing this question, it seems the greatest obstacle to carbon graphite heatsinks on a large scale is the manufacturing difficulty (read high costs) to create similar heatsinks to those that today are of aluminum or copper.  Also recognize that the equivalent carbon graphite heat sink would be very fragile, and could not withstand even those small forces caused by the common clamping mechanisms.

Regards,
jtleon


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## panchoman (Sep 26, 2007)

jtleon said:


> Note that carbon graphite in pencil lead is only a small percentage carbon graphite, the remainder is a polymer that binds the particles together.  In this form, the conductivity is very poor, given the low particle population.
> 
> After reviewing this question, it seems the greatest obstacle to carbon graphite heatsinks on a large scale is the manufacturing difficulty (read high costs) to create similar heatsinks to those that today are of aluminum or copper.  Also recognize that the equivalent carbon graphite heat sink would be very fragile, and could not withstand even those small forces caused by the common clamping mechanisms.
> 
> ...



well if we add diamond supports to the carbon graphite, the we get a 100k heatsink


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## KennyT772 (Sep 26, 2007)

More importantly than the metal of the heatsink is the design. That cannot be forgotten. Properly placed heat pipes are the hardest to find in todays heatsinks. 

heat pipes should not be arranged in a inline fashion, or near the outer edge of the heatsink. Many of todays heatsinks group the heat pipes so that the fin area becomes saturated with heat, while other areas never even get warm. The more even the distribution of heat pipes the better the performance end of story. 

I believe the best design would be a dual tower style like the Thermalright fx14 with 6 heat pipes. If the heat pipes were pressed square then laid side by side to form a base you would have direct contact with the IHS and the best thermal transfer. You then put a block on top of them (for mounting and rigidity). Each of the 6 heat pipes then should be staggered  in the tower for the best distribution. Add a fan with a shroud on each side (to normalize pressure and turbulence) and you have the near perfect heatsink. Maybe I should design this in CAD and send it into Thermalright... This could be easily done with Thermalright's designs and would would great. Anyone think I should send it in?


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## panchoman (Sep 26, 2007)

KennyT772 said:


> More importantly than the metal of the heatsink is the design. That cannot be forgotten. Properly placed heat pipes are the hardest to find in todays heatsinks.
> 
> heat pipes should not be arranged in a inline fashion, or near the outer edge of the heatsink. Many of todays heatsinks group the heat pipes so that the fin area becomes saturated with heat, while other areas never even get warm. The more even the distribution of heat pipes the better the performance end of story.
> 
> I believe the best design would be a dual tower style like the Thermalright fx14 with 6 heat pipes. If the heat pipes were pressed square then laid side by side to form a base you would have direct contact with the IHS and the best thermal transfer. You then put a block on top of them (for mounting and rigidity). Each of the 6 heat pipes then should be staggered  in the tower for the best distribution. Add a fan with a shroud on each side (to normalize pressure and turbulence) and you have the near perfect heatsink. Maybe I should design this in CAD and send it into Thermalright... This could be easily done with Thermalright's designs and would would great. Anyone think I should send it in?



sure, sounds great. its never hurts to try (well most of the time)


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## Chewy (Sep 26, 2007)

woot go Kenny GO!


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## KennyT772 (Sep 26, 2007)

Hmm...Now I just need to find time to skip class and go down to the CAD lab at school. The CAD teacher (Mr. Foster) has a dual 30" lcd setup for his main pc...I drool over it. Hes running dual 7600's, one card running the lcds and the other outputing to his projector (a 1600x1200 beast in itself).


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## panchoman (Sep 26, 2007)

KennyT772 said:


> Hmm...Now I just need to find time to skip class and go down to the CAD lab at school. The CAD teacher (Mr. Foster) has a dual 30" lcd setup for his main pc...I drool over it. Hes running dual 7600's, one card running the lcds and the other outputing to his projector (a 1600x1200 beast in itself).



whoa sick. lemme guess, the school funded all of that?

and im sure the cad teacher will give you a pass to skip classes and all.


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## KennyT772 (Sep 26, 2007)

panchoman said:


> whoa sick. lemme guess, the school funded all of that?



Part of the CAD grant yeah. Every classroom has a dell workstation pc, 1280x1024 lcd monitor, document camera, dvd/vrc combo, and a 1280x1024 projector. Not to shabby if I say so myself. I'd say theres over 500 computers total in my school and we only have around 1300 students. Oh each teacher also has a hp laptop. Yeah..property taxes are insane around here.


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## Chewy (Sep 26, 2007)

I take it THATS how cad should be  not like on my home computer  someday I will learn some cad.. but atm I dont have the time to.


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## panchoman (Sep 26, 2007)

KennyT772 said:


> Part of the CAD grant yeah. Every classroom has a dell workstation pc, 1280x1024 lcd monitor, document camera, dvd/vrc combo, and a 1280x1024 projector. Not to shabby if I say so myself. I'd say theres over 500 computers total in my school and we only have around 1300 students. Oh each teacher also has a hp laptop. Yeah..property taxes are insane around here.



your in college right? and cad is what?


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## kwchang007 (Sep 26, 2007)

KennyT772 said:


> Part of the CAD grant yeah. Every classroom has a dell workstation pc, 1280x1024 lcd monitor, document camera, dvd/vrc combo, and a 1280x1024 projector. Not to shabby if I say so myself. I'd say theres over 500 computers total in my school and we only have around 1300 students. Oh each teacher also has a hp laptop. Yeah..property taxes are insane around here.



We have like...6 computer labs (30 comps each) a computer for a teacher in every room (ugh all Dell's) probably around 100-150 of those.  Then each department has like one or two mobile units (laptop, projector on a cart).  Many rooms also have projectors.  So I'd say my school has eh almost 300 computers, not to shabby for a private high school.


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## panchoman (Sep 26, 2007)

lol i'm in public and we're poor. the private schools here are huge, they have better specs then what change said above lol, crazy amount of money. smart boards in every room, etc. but its about 19k a year to go to em so..


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## kwchang007 (Sep 26, 2007)

panchoman said:


> lol i'm in public and we're poor. the private schools here are huge, they have better specs then what change said above lol, crazy amount of money. smart boards in every room, etc. but its about 19k a year to go to em so..



Oh....I got to the "poor" private schools....aka Catholic.  We're currently in need of like 5 million for our refurbishing of the athletics place.  (new gym, field, stadium, track, the works )


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## panchoman (Sep 26, 2007)

kwchang007 said:


> Oh....I got to the "poor" private schools....aka Catholic.  We're currently in need of like 5 million for our refurbishing of the athletics place.  (new gym, field, stadium, track, the works )



our school spends all our money on sports. where like the sports center for the county. we've got like 3 baseball fields, 2 football fields, 6 tennis courts, a track, lots of seating for the sport events, project adventure, which is like climbing buildings and free falling and stuff like that.. we've got 2 indoor gyms plus a weight lifting room. and we just refurbished both of our computer labs with smartboards and imacs. and many teachers have imacs and smartboards too.


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## kwchang007 (Sep 26, 2007)

panchoman said:


> our school spends all our money on sports. where like the sports center for the county. we've got like 3 baseball fields, 2 football fields, 6 tennis courts, a track, lots of seating for the sport events, project adventure, which is like climbing buildings and free falling and stuff like that.. we've got 2 indoor gyms plus a weight lifting room. and we just refurbished both of our computer labs with smartboards and imacs. and many teachers have imacs and smartboards too.



Lucky you....we have one real baseball field, two practice baseball fields, pleanty of practice fields, we will have a state of the art track, football field, and gym when they're done.  Idk what they're going to do with our tennis courts though.


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## panchoman (Sep 26, 2007)

kwchang007 said:


> Lucky you....we have one real baseball field, two practice baseball fields, pleanty of practice fields, we will have a state of the art track, football field, and gym when they're done.  Idk what they're going to do with our tennis courts though.



lol, our school's trying to pass a budget to build some more track and field stuff. they want to build a new track and add lots of other stuff, vaulting, javalien, pole jumping, etc.


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## kwchang007 (Sep 26, 2007)

panchoman said:


> lol, our school's trying to pass a budget to build some more track and field stuff. they want to build a new track and add lots of other stuff, vaulting, javalien, pole jumping, etc.



On old track we had vaulting...no javaline, but discus and some other throwing thing, and we also had pole jumping.  We're a pretty sports focused school (all guys...we better be good...but it also sucks not having girls)


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## KennyT772 (Sep 26, 2007)

I goto Mona Shores High School, not a college. In total we have about 120 pcs in our library, 4 COWs (Computers on wheels.) Which have 16 laptops, a wifi accesspoint, laser printer. Then we have the CAD lab 35pcs, 4 computer labs with 25pcs each, 3 smart boards, a smartcart (the system I described before) in each class, a regular computer for students in each class, a laptop for each teacher, then the office pcs. My school also has a full NAS system with 20tb of total space, on a 10gbit backbone. All of our 170 security camera's are also networked and stored in database form. 

Shores is the top 10 in the state for Hockey, Basketball, Soccer, volleyball, tennis, golf, swimming, cross country, track, marching band, orchestra, choir, debate, theatrics, and theres prolly more i cant think of. We have two full size gyms, weight room, medium size football stadium (the only thing we suck at), 3 soccer fields, 5 baseball fields, 4 tennis courts, cross country course, full auditorium with seating for 600 (playing css on that projector is fun), two band rooms, two choir rooms (all have sound dampening and acoustic tuning), 7 soundproof practice rooms, full production stage, a/v studio for daily announcements, 1,800 lockers, 600person cafeteria, and somewhere around 50 classrooms.


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## panchoman (Sep 26, 2007)

cool, but we're not that bad considering we're a very poor public school lol


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## kwchang007 (Sep 26, 2007)

Kenny, you go to a rich school I'm guessing?  We were in the top 10 I think nationally in basketball last season, or maybe that was the year before.  We're probably top 10 in our state in all sports except in varsity football, and some of the more obscure sports.  Our wrestling team was like 1 or 2 in the state.  We have an auditorium with seating for probably 500-600 people.  Our gym can hold 1200+ people.  Our band....well we suck, lol.  We have a speech and debate team that sent like 5 or 6 guys to nationals last year.  We've had all 5's in ap chem for the past like 5 or 6 years.  Last year we had 5's in ap bio as well.  There's more...but I didn't memorize things like that, lol.  Oh and our lunches ROCK.


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## panchoman (Sep 26, 2007)

our lunchs poon. we get professional companies to cater our school, plus its an open campus so we can just step out during our free time and go over to the bunch of restaurants and eat there. our auditorium can hold 900 people lol. our band is kickass we have like a zillion trophies and we get to go a cruise each year. we have shitloads of ap classes with really good teachers. all the bad teachers get fired lol.


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## AsRock (Sep 26, 2007)

freaksavior said:


> hmm, so basically what your saying is, it is best to have a copper plate/base, then aluminum fins.




Part of the reason i got the COOLER MASTER GeminII and found out that in my case at least it don't even need the fans on it.

46c is the hotest i seen it without fans with a .4 overclock on CPU. Most times it don't even reach 42c underload according to Speedfan.

EDIT: in thats in a room @ 85f


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## kwchang007 (Sep 26, 2007)

panchoman said:


> our lunchs poon. we get professional companies to cater our school, plus its an open campus so we can just step out during our free time and go over to the bunch of restaurants and eat there. our auditorium can hold 900 people lol. our band is kickass we have like a zillion trophies and we get to go a cruise each year. we have shitloads of ap classes with really good teachers. all the bad teachers get fired lol.



My middle school got a superior for like 30 years straight.  Superior being the highest grade possible.


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## panchoman (Sep 27, 2007)

okay, lets take this out in the teen thread instead, i thikn we've hijacked this thread enough.


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## KennyT772 (Sep 27, 2007)

Agreed...


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## [I.R.A]_FBi (Sep 27, 2007)

aluminum is jsut used for cost cutting costco, lol


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## Athlon2K15 (Sep 27, 2007)

so we could use pencil lead for TIM?


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## panchoman (Sep 27, 2007)

not pencil lead cause its got polymers and crap in it but pure carbon graphite, yeah..


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## largon (Sep 27, 2007)

Polymers are there only in small amounts to make the stuff softer (= "HB2", and so on). 
It's mainly clay laced with graphite dust. 

Barely conducts electricity thanks to the graphite, not good for heat transfer.


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## freaksavior (Sep 27, 2007)

wow, this thread went a little further than expected.


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## jtleon (Sep 27, 2007)

*Do It Kenny...Send in the new design to Thermalright*



KennyT772 said:


> I believe the best design would be a dual tower style like the Thermalright fx14 with 6 heat pipes. If the heat pipes were pressed square then laid side by side to form a base you would have direct contact with the IHS and the best thermal transfer. You then put a block on top of them (for mounting and rigidity). Each of the 6 heat pipes then should be staggered  in the tower for the best distribution. Add a fan with a shroud on each side (to normalize pressure and turbulence) and you have the near perfect heatsink. Maybe I should design this in CAD and send it into Thermalright... This could be easily done with Thermalright's designs and would would great. Anyone think I should send it in?



Excellent observations....And while your at it, remind Thermalright that most fans are round, and cast a circular flow pattern, i.e. the HS fins should be arranged in a circular pattern around the fan for best uniform flow, thus eliminating dead spots.

Regards,
jtleon


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## AddSub (Sep 27, 2007)

When it comes to aluminum vs. copper comparisons, copper is king in every aspect except cost. Although, many retailers do charge same or more for their aluminum parts (vs. copper) and I bet that’s where some of the confusion comes from. If it costs more that means it's better right? Not necessarily.

Anyone remember the whole aluminum vs. steel lunacy from few years ago when aluminum cases started coming out in numbers?


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