Heatsinks

[jac0b84]

Hey,

I am trying to clarify the reasoning for Zalman to make most of their parts in either all copper, copper and aluminum or all aluminum. I understand that copper is a better conducter while aluminum is lighter but are either of these enough to affect performance, stress on a vertical motherboard and its CPU or price??


THanks in advance,


Peace

 

[Maximilian]

Yes, copper is the better conductor, and i seem to remember its the one that costs more. TBH i dont think it would matter too much which one you buy with regards to stress, the mobo should be able to hold on any heatsink. Dont know about the performance difference though, i would always go with copper just to be sure.

 

[Matthias99]

Originally posted by: Soviet
Yes, copper is the better conductor, and i seem to remember its the one that costs more. TBH i dont think it would matter too much which one you buy with regards to stress, the mobo should be able to hold on any heatsink. Dont know about the performance difference though, i would always go with copper just to be sure.

Actually, some of their all-copper heatsinks are heavy enough to meet or exceed the load ratings of some motherboards. It's siginficantly heavier than aluminum. You'd certainly need a metal backplate if you were mounting one on an A64 board (some early boards shipped with plastic backplates, which work fine for lightweight aluminum heatsinks but will bend or break if you try to put really heavy ones on).

Basically, Copper = heavier, more expensive, conducts heat better than almost anything (silver and gold are better, but that's about it). Aluminum = cheaper, lighter, doesn't conduct quite as well.

 

[xanis]

Copper does indeed conduct heat better than some other metals, and it is therefore, it is found in most aftermarket heatsinks. Aluminum does not conduct heat as well as copper does, but it is cheaper and lighter and also used in heatsinks. If you notice, aluminum is more commonly used in high-quality computer cases to keep them extra cool. Lian-Li cases are made of aluminum.

 

[Jeff7]

One other thing not mentioned:
What I've read a lot is that copper conducts heat better than aluminum, but copper isn't as willing to let that heat go. So rather than have air contacting the copper, the aluminum does so, and it then dissipates the heat.

 

[Jiggz]

Originally posted by: Jeff7
One other thing not mentioned:
What I've read a lot is that copper conducts heat better than aluminum, but copper isn't as willing to let that heat go. So rather than have air contacting the copper, the aluminum does so, and it then dissipates the heat.

This is actually accurate. Cooper may conduct heat faster than aluminum but lags when releasing it compare to aluminium.

 

[Fullmetal Chocobo]

Originally posted by: Matthias99

Originally posted by: Soviet
Yes, copper is the better conductor, and i seem to remember its the one that costs more. TBH i dont think it would matter too much which one you buy with regards to stress, the mobo should be able to hold on any heatsink. Dont know about the performance difference though, i would always go with copper just to be sure.

Basically, Copper = heavier, more expensive, conducts heat better than almost anything (silver and gold are better, but that's about it). Aluminum = cheaper, lighter, doesn't conduct quite as well.

Where did you get this information?
Thermal Conductivity:
Silver = 4.29 W/ (cm x K) @ 1 atm, 25C
Copper = 4.01 W/ (cm x K) @ 1 atm, 25C
Gold = 3.17 W/ (cm x K) @ 1 atm, 25C
Aluminum = 2.37 W/ (cm x K) @ 1 atm, 25C
Platinum = .0716 W/ (cm x K) @ 1 atm, 25C

So silver is the best, followed by copper, then gold, etc.
Density
Aluminum = 2.70 g/cm^3
Copper = 8.96 g/cm^3
Silver = 10.5 g/cm^3
Gold = 19.3 g/cm^3
Platinum = 21.5 g/cm^3

And here, you can see that Aluminum definitely shows it's advantages in weight, being about 1/4 the density as copper, and roughly 1/5 the density as the best conductor, silver.

 

[svi]

What I've read a lot is that copper conducts heat better than aluminum, but copper isn't as willing to let that heat go. So rather than have air contacting the copper, the aluminum does so, and it then dissipates the heat.

This is a myth, actually. While it is true that aluminum radiates heat better than copper, the vast majority of heat transfer between a CPU heatsink and air occurs through convection. Heat convection is a direct function of the heatsink's thermal conductivity and the air's thermal conductivity (convectivity if you will, I guess).

In other words, if it conducts heat from the CPU to its fins faster, heat will go from its fins to air faster.

 

[Matthias99]

Originally posted by: tasburrfoot78362

Originally posted by: Matthias99

Originally posted by: Soviet
Yes, copper is the better conductor, and i seem to remember its the one that costs more. TBH i dont think it would matter too much which one you buy with regards to stress, the mobo should be able to hold on any heatsink. Dont know about the performance difference though, i would always go with copper just to be sure.

Basically, Copper = heavier, more expensive, conducts heat better than almost anything (silver and gold are better, but that's about it). Aluminum = cheaper, lighter, doesn't conduct quite as well.

Where did you get this information?
Therman Conductivity:
Silver = 4.29 W/ (cm x K) @ 1 atm, 25C
Copper = 4.01 W/ (cm x K) @ 1 atm, 25C
Gold = 3.17 W/ (cm x K) @ 1 atm, 25C
Aluminum = 2.37 W/ (cm x K) @ 1 atm, 25C
Platinum = .0716 W/ (cm x K) @ 1 atm, 25C

So silver is the best, followed by copper, then gold, etc.

My bad. Gold's a better electrical conductor than copper, but not a better thermal conductor (see, this is why I dropped engineering and just majored in CS). Sort of irrelevant, since I doubt anyone would be making a solid gold or silver heatsink anyway.

 

[Fullmetal Chocobo]

Didn't mean to jump on ya, but that bugs me, as it gets posted wrong so much. (About the sixth time I've had to refer to the Periodic Table on my PDA) And that isn't entirely true. There is a DangerDan liquid cooling water block that is completely made out of silver (not counting the mounting part). Very nice!!

 

[Varun]

Originally posted by: Xanis
Copper does indeed conduct heat better than some other metals, and it is therefore, it is found in most aftermarket heatsinks. Aluminum does not conduct heat as well as copper does, but it is cheaper and lighter and also used in heatsinks. If you notice, aluminum is more commonly used in high-quality computer cases to keep them extra cool. Lian-Li cases are made of aluminum.

The material used in the construction of the case does not affect how cool it runs, which is a common myth. Airflow is the way to cool your computer.

Originally posted by: Matthias99

My bad. Gold's a better electrical conductor than copper, but not a better thermal conductor (see, this is why I dropped engineering and just majored in CS). Sort of irrelevant, since I doubt anyone would be making a solid gold or silver heatsink anyway.

Actually, copper is better than gold for conducting electricity as well. Silver is the best, followed by copper, followed by gold. The benefit of gold is the corrosion resistance, which is why many connectors are gold plated.

 

[YOyoYOhowsDAjello]

Originally posted by: Matthias99

Originally posted by: tasburrfoot78362

Originally posted by: Matthias99

Originally posted by: Soviet
Yes, copper is the better conductor, and i seem to remember its the one that costs more. TBH i dont think it would matter too much which one you buy with regards to stress, the mobo should be able to hold on any heatsink. Dont know about the performance difference though, i would always go with copper just to be sure.

Basically, Copper = heavier, more expensive, conducts heat better than almost anything (silver and gold are better, but that's about it). Aluminum = cheaper, lighter, doesn't conduct quite as well.

Where did you get this information?
Therman Conductivity:
Silver = 4.29 W/ (cm x K) @ 1 atm, 25C
Copper = 4.01 W/ (cm x K) @ 1 atm, 25C
Gold = 3.17 W/ (cm x K) @ 1 atm, 25C
Aluminum = 2.37 W/ (cm x K) @ 1 atm, 25C
Platinum = .0716 W/ (cm x K) @ 1 atm, 25C

So silver is the best, followed by copper, then gold, etc.

My bad. Gold's a better electrical conductor than copper, but not a better thermal conductor (see, this is why I dropped engineering and just majored in CS). Sort of irrelevant, since I doubt anyone would be making a solid gold or silver heatsink anyway.

Cu Electrical resistivity (20 °C) 16.78 nO·m
Au Electrical resistivity (20 °C) 22.14 nO·m

Edit: oops, Varun said it first

 

[Fullmetal Chocobo]

Why do PSUs often use the harder cable, and not copper? (I think it is steel, but I'm not sure). I've been soldering a lot of power supply cables lately, and it's made me miss soldering copper very much.

 

[Varun]

Originally posted by: tasburrfoot78362
Why do PSUs often use the harder cable, and not copper? (I think it is steel, but I'm not sure). I've been soldering a lot of power supply cables lately, and it's made me miss soldering copper very much.

It's likely aluminum. Aluminum is cheaper, and has higher conductance per unit of mass than copper.

 

[Fullmetal Chocobo]

Okay... I figured it was the bit about it being cheaper, but I didn't know the other part. Damn that stuff is a bitch to solder.

 

[Matthias99]

Originally posted by: Varun

Originally posted by: Matthias99

My bad. Gold's a better electrical conductor than copper, but not a better thermal conductor (see, this is why I dropped engineering and just majored in CS). Sort of irrelevant, since I doubt anyone would be making a solid gold or silver heatsink anyway.

Actually, copper is better than gold for conducting electricity as well. Silver is the best, followed by copper, followed by gold. The benefit of gold is the corrosion resistance, which is why many connectors are gold plated.

Man, I suck at teh EE. Again, this is why I majored in CS.

 

[dainthomas]

Copper is around $.12/oz, and silver is around $7.60/oz.

Therefore, a silver XP-90 would be around $180 just for materials. Would be totally pimpin, though.

 

[jac0b84]

So if I have a metal backing plate I should be ok on the stress on the MOBO?

Would this come with the heatsink theoretically?

 

[Varun]

Originally posted by: jac0b84
So if I have a metal backing plate I should be ok on the stress on the MOBO?

Would this come with the heatsink theoretically?

Yes they come with the heatsinks