Thin or thick Aluminum fins are better?

[Knight47]

I'm wondering which one would be better, a Aluminum heat sink with 1mm base and 1mm fins, 3mm base and 1mm fins or 3mm base and 3mm fins?

 

[P4-630]

Thin fins, so there is more surface to cool.

3mm base and 1mm fins.

What are you trying to cool?

 

[Veseleil]

Active or passive cooling makes a difference as well. Wider gaps for passive.

 

[Knight47]

Thin fins, so there is more surface to cool.

3mm base and 1mm fins.

What are you trying to cool?

I'm planning to do some diy motherboard(vrm, chipset) and gpu (vrm,vram) cooling. I have some s478 coolers that have thicker base or use something like this https://www.ampul.eu/en/coolers/4466-aluminum-heat-sink-60x31x12mm-with-hot-melt-adhesi

Maybe I could repurpose a MC1 Pro, would the heatpipe compensate for the lack of fins?

Mobo chipset doesnt get a lot of airflow, it sits at 68-70 celsius idle.

 

[Lei]

Copper.

 

[lilhasselhoffer]

If the cooler gets any air you want thinner fins (1 mm base, 3 mm fins), as the increased surface area is going to transfer heat to the surrounding environment.

If the cooler is entirely passive you want thicker and triangular fins (3 mm, 3 mm). The former to add thermal mass and the later to promote convection currents to improve performance. Don't expect miracles. Convection in such a situation is small...so you're looking at thermal mass to try and create the desired temperature equilibrium.


Your stated goal is to cool the chipset though...so this isn't going to perform any miracles without airflow. If you've already got that, then the answer is that there's not a lot to in here. You don't list a computer...so my guess is only that this is fine. Some chipsets do run hot...but that's way cooler than your average thermal max for a CPU.

 

[micropage7]

the thick base would eat the heat more and thinner fins would release the heat more

 

[AusWolf]

the thick base would eat the heat more and thinner fins would release the heat more

This.

Thick fins have higher heat capacity, that is, they are slower to warm up or cool down. Thinner fins can create more surface area to conduct the heat, as they require less space. You can't say one is better than the other. It really depends on the application. My logic would say that short, bursty heat loads would work better with thicker fins, while prolonged heat is better conducted by more, but thinner fins and/or active cooling.

 

[Redwoodz]

This.

Thick fins have higher heat capacity, that is, they are slower to warm up or cool down. Thinner fins can create more surface area to conduct the heat, as they require less space. You can't say one is better than the other. It really depends on the application. My logic would say that short, bursty heat loads would work better with thicker fins, while prolonged heat is better conducted by more, but thinner fins and/or active cooling.

^ In an average,3mmx3mm would have the most cooling potential because of the total surface area and mass.

 

[P4-630]

Just don't use stainless/steel for heatsinks lol...

 

[evernessince]

Copper.

It's a common assumption that copper is a better material for heatsink fins due to it's higher thermal conductivity but copper's effusivity is lower than that of Aluminum. Copper is better at carrying heat away but it's inferior at dissipating it, hence why aluminum is used for heatsink fins.

In regards to the OP's question, thin dense fins are better for active cooling while thick more sparsely populated fins are better for passive. A thicker base allows the sink to more easily absorb temperature spikes and is recommended for passive cooling.

 

[freeagent]

My Le Grand Macho RT has thick fins for passive use, but it also responds well to a high speed fan. All of my TR coolers can be used semi passively with my current hardware.

 

[Knight47]

If the cooler gets any air you want thinner fins (1 mm base, 3 mm fins), as the increased surface area is going to transfer heat to the surrounding environment.

If the cooler is entirely passive you want thicker and triangular fins (3 mm, 3 mm). The former to add thermal mass and the later to promote convection currents to improve performance. Don't expect miracles. Convection in such a situation is small...so you're looking at thermal mass to try and create the desired temperature equilibrium.


Your stated goal is to cool the chipset though...so this isn't going to perform any miracles without airflow. If you've already got that, then the answer is that there's not a lot to in here. You don't list a computer...so my guess is only that this is fine. Some chipsets do run hot...but that's way cooler than your average thermal max for a CPU.

One of them is a Gigabyte 970A-UD3 where the Northbridge runs at 68-70 celsius and gets even hotter when doing demanding stuff, its sandwiched between the tower cooler and gpu, I did try using a 40mm fan, but it's too noisy for my liking.

The other board is a Asrock H610M-HDV that I plan to put in a small 20*20*7cm box and would like to cool the vrm, thinking about putting a MC1 Pro on it so that the heatpipes are on the sides.

 

[P4-630]

Northbridge runs at 68-70 celsius and gets even hotter when doing demanding stuff

Some good effective heatsinks for that:
I used this one with a fan, my dad got this system and still using it.

HR-05, Northbridge Heatsink

www.quietpc.com

Or a thermaltake one, also had this one the southbridge:

Press Release

 

[Lei]

It's a common assumption that copper is a better material for heatsink fins due to it's higher thermal conductivity but copper's effusivity is lower than that of Aluminum. Copper is better at carrying heat away but it's inferior at dissipating it, hence why aluminum is used for heatsink fins.

In regards to the OP's question, thin dense fins are better for active cooling while thick more sparsely populated fins are better for passive. A thicker base allows the sink to more easily absorb temperature spikes and is recommended for passive cooling.

Thanks

Copper vs. Aluminum - Thermal Conductivity & Radiation

First of all, I want to lay some ground rules, because I have seen this go way out of bounds on many other forums. If you're going to make a claim, please voice your opinion and state WHY. The question we are focusing on related to processor cooling, specifically with air cooling, not water...

www.techpowerup.com

I always love to stay hungry, stay foolish. Link

May be if vrams are close to pcb giant heatsink, can connect them with thermal tapes.

 

[Vya Domus]

For low power passive use case the thicker fins might be of better use.

 

[Shrek]

Copper vs. Aluminum - Thermal Conductivity & Radiation

First of all, I want to lay some ground rules, because I have seen this go way out of bounds on many other forums. If you're going to make a claim, please voice your opinion and state WHY. The question we are focusing on related to processor cooling, specifically with air cooling, not water...

www.techpowerup.com

That link claims

"Copper is better at conducting heat than aluminum, but aluminum is able to radiate the heat into the air better than copper because of its lower density."

I beg to differ; how does low density help?

 

[mechtech]

Just don't use stainless/steel for heatsinks lol...

Use stainless steel often for heat exchangers when corrosion and or long life is an issue. Copper good but erodes faster with 400L/min raw river water flowing through it.

As for the OP
If the motherboard will be vertical make sure the fins are perpendicular to the ground so rising air can move through easily. Personally I would use a pin fin heat sink for this application, but whatever floats your boat.

I used to have a block like this but about 3-4mm thick base and 50mm tall pins and it worked really good for that.

 

[Lei]

That link claims

"Copper is better at conducting heat than aluminum, but aluminum is able to radiate the heat into the air better than copper because of its lower density."

I beg to differ; how does low density help?

This doesn't answer your query, but makes me suck my thumb while reading it:

Emissivity Coefficients of Common Materials: Data & Reference Guide

The radiation heat transfer emissivity coefficients for some common materials like aluminum, brass, glass and many more.

www.engineeringtoolbox.com

Hmm, let's put a paper on our vram and bury that under soil. Excellent surface heat emissivity
Look, magnesium is less dense than both Cu and Al.

 

[Knight47]

Some good effective heatsinks for that:
I used this one with a fan, my dad got this system and still using it.

HR-05, Northbridge Heatsink

www.quietpc.com

Or a thermaltake one, also had this one the southbridge:

Press Release

I would put a tower cooler on it, but there isn't any clearance

Some good effective heatsinks for that:
I used this one with a fan, my dad got this system and still using it.

HR-05, Northbridge Heatsink

www.quietpc.com

Or a thermaltake one, also had this one the southbridge:

Press Release

I would really like to put a tower cooler on it, but there's no room for it