What provides better heat disappation...copper or aluminium

inbow78

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Nov 6, 2006
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I am thinking about getting a new heat sink for my cpu. Which is going to cool better copper or aluminium?
 

Fullmetal Chocobo

Moderator<br>Distributed Computing
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May 13, 2003
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Thermal Conductivity, expressed in W/(cmK) @ 1 atm, 25 degrees Celsius:
silver = 4.29
copper = 4.01
gold = 3.17
aluminum = 2.37
nickel = 0.907
lead = 0.353
mercury = 0.0834

Thermal Heat Capacity, expressed in J/(gK) @ 1 atm, 25 degrees Celsius:
aluminum = 0.897
nickel = 0.444
copper = 0.385
silver = 0.235
mercury = 0.14
gold = 0.129
lead = 0.129

Thermal diffusivity (thermal conductivity / thermal capacity):
gold = 24.573
silver = 18.255
copper = 10.415
lead = 2.736
aluminum = 2.642
nickel = 2.042
mercury = 0.595
 

Ayah

Platinum Member
Jan 1, 2006
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Copper is better than Aluminum.
And silver is even better (could you afford to get one made)
 

Agent11

Diamond Member
Jan 22, 2006
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the abit aw9max has silver heatpipes.. wish more companies would offer more exotic metals for the price you shell out for a top of the line board.
 

soydios

Platinum Member
Mar 12, 2006
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Copper conducts more heat.
Aluminum is lighter, but it holds the heat more than copper (which is bad, you want it to get rid of heat quickly).
 

Mark R

Diamond Member
Oct 9, 1999
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The only property that is of relevance to heatsink design is 'thermal conductivity' - copper is the winner here (discounting silver due to its cost).

The thermal capacity/diffusivity, etc. are irrelevant.

While Aluminium will store more heat energy in it, all this means is that with copper, the heatsink will get up to running temperature faster when the CPU is switched on, and cool down quicker when switched off.

Some people say that aluminium 'holds onto heat longer' as if this is something bad for heatsinks - it isn't. It's irrelevant. All it means is that the heatsink temperature changes more slowly - it has no effect on the actual temperature it gets to.

Of course, heat pipes change things - heat pipes have 'conductivity' tens, or even hundreds, of times higher than copper. This allows heat to be moved a long way to multiple fins.
 

Navid

Diamond Member
Jul 26, 2004
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Mark R is right. The only thing that matters if cooling the chip is your only objective is thermal conductivity.

The only disadvantage of Copper compared to Aluminum is its weight. Some copper sinks are very heavy. That is why you see sinks that have both Copper and Aluminum in them.
 

l0cke

Diamond Member
Dec 12, 2005
3,790
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Originally posted by: Fullmetal Chocobo
Thermal Conductivity, expressed in W/(cmK) @ 1 atm, 25 degrees Celsius:
silver = 4.29
copper = 4.01
gold = 3.17
aluminum = 2.37
nickel = 0.907
lead = 0.353
mercury = 0.0834

Thermal Heat Capacity, expressed in J/(gK) @ 1 atm, 25 degrees Celsius:
aluminum = 0.897
nickel = 0.444
copper = 0.385
silver = 0.235
mercury = 0.14
gold = 0.129
lead = 0.129

Thermal diffusivity (thermal conductivity / thermal capacity):
gold = 24.573
silver = 18.255
copper = 10.415
lead = 2.736
aluminum = 2.642
nickel = 2.042
mercury = 0.595

What a about diamond? I thought it went more like alu>gold>copper>silver>diamond
 

Agent11

Diamond Member
Jan 22, 2006
3,535
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http://en.wikipedia.org/wiki/Material_properties_of_diamond

'Thermal properties

Unlike most electrical insulators, diamond is a good conductor of heat because of the strong covalent bonding within the crystal. Most natural blue diamonds contain boron atoms which replace carbon atoms in the crystal matrix, and also have high thermal conductance. .999-12C monocrystalline synthetic diamond has the highest thermal conductivity of any known solid at room temperature: 2000?2500 W·m/m2·K (200?250 W·mm/cm2·K)[1], five times more than copper. Because diamond has such high thermal conductance it is already used in semiconductor manufacture to prevent silicon and other semiconducting materials from overheating. At lower temperatures conductivity becomes even better as its Fermi electrons can match the phononic normal transport mode near the Debye point[2], and transport heat swifter, to overcome the drop of specific heat with the fewer quantal microstates, to reach 41,000 W·m/m2·K at 104 K. The same diamond at .99999-12C is predicted to 200,000 W·m/m2·K (20 kW·mm/cm2·K)[1].

Diamond's thermal conductivity is made use of by jewellers and gemologists who may employ an electronic thermal probe to separate diamonds from their imitations. These probes consist of a pair of battery-powered thermistors mounted in a fine copper tip. One thermistor functions as a heating device while the other measures the temperature of the copper tip: if the stone being tested is a diamond, it will conduct the tip's thermal energy rapidly enough to produce a measurable temperature drop. This test takes about 2?3 seconds. However, older probes will be fooled by moissanite, an imitation of diamond introduced in 1998 which has a similar thermal conductivity.'

Somehow I doubt we will see a zalman diamond edition though ;P