- Joined
- Jan 15, 2004
A big thanks to rogerdugans and archilochus for helping me with this sticky.
The following is an article written by me with the help of the above two people (with the exclusion of the part added by Super Nade). It is therefore my intellectual property and if you wish to copy this onto your webpage please contact me for permission.
Terminology:
Rheostat: Something that controlls the voltage a fan receivs, fan controllers use rheostats, see this excellent guide on how to pick one.
Heatpipes: The topic is too complex for this guide, however here is an excellent link
The most important decision you will have to make when choosing a heatsink:
What is the noise level I am willing to live with, some factors for that are do I live alone, is this computer in my bedroom, and will it run all day and night. Those questions should guide you to selecting whether you want a high performance one or not. If you like to overclock, you will propably need one of the high performance heatsinks and a strong fan, because when overclocking the processor will get hotter (assuming you raise the voltage, even if not better safe then sorry). However just because you chose the high performance route does not mean it can not run quietly (unless you picked a fan labelled as loud) just get a fan controller or Rheostat and quiet it down at night.
Materials: copper and aluminum are the most popular materials in use and copper generally performs better than aluminum. Copper is heavier and more costly however, so many sinks are actually a combination of the two: a "slug" of copper for the cpu core contact area and the rest made of cheaper aluminum. However a pure copper heatsink will perform better then a pure aluminum one (assuming there are no heatpipes being used).
Following is added by Super Nade.
{
If somebody went off into the deep end and wanted to know really why Cu is a better radiator than Al, this rough calculation can be used.
Thermal Conductivity of copper:-
http://www.vcs.ethz.ch/chemglobe/ptoe/_/29.html
[4.01 W/cmK]
Thermal Conductivity of Aluminium:
http://www.vcs.ethz.ch/chemglobe/ptoe/_/13.html
[2.37 W/cmK]
I checked these numbers with the CRC handbook.
My thoughts:-
We know that Planck's radiation law is true. But it is valid in the form seen in textbooks for a black body.So we use Stefan's Law.We are talking about convection/conduction and radiation in our analysis.
Stefan's Law:
P=e x sigma x A x (T^4-t^4)
P---->power radiated
A---->radiating area
sigma----->stefans constant
e---->emissivity {=1 if its a black body}
T/t----->temprature of the radiator/surroundings
Now assuming all things being the same i.e A,T/t, Sigma and convectional losses, the critical parameter here is e.
eCopper=0.119
eAluminium=0.05
http://www.engineeringtoolbox.com/36_447.html
So, how is Aluminum better than copper in this context?
Now, let us analyse the convection/conduction.
As show above the thermal conductivity of Cu > Al. As the thermal conductivity of air is assumed constant for both experiments, Cu wins again!
}
Different heatsink styles:
The regular old heatsink: Usually a square base made out of aluminum or copper and then fins attached on top. The higher quality blocks have many thin fins, so they have the most surface area they also require a stronger fan to run. The lower end blocks tend to have thick fins with a good amount of space in between. This requires a less powerful fan and are cheaper to make.
The tower heatsink: A heatsink, has a square base like a normal one. However then there are copper heatpipes going out to a rather large tower of copper or aluminum. These heatsinks are usually large enough to hold two fans. However they do not outperform a quality "normal" heatsink running on one fan. Also, the same fin density principle applies here see above.
Sockets:
Socket 478: This is the socket the new pentium 4's use, the most common.
Socket A (462): Athlons/Durons/Athlon XP's the main AMD line at this point
Socket 754: AMD Athlon 64's this socket will not be updated for too much longer
Socket 939: The new Athlon 64's will be out for this socket
Socket 940: AMD Athlon 64 FX's and Opterons are on this socket
Mounting:
On all except two socket, there is only one way to mount a heatsink, that is usually through bolting it on there. The Socket A users have a choice between bolting it on and using the clips. The clips are fine for light heatsinks, but on heavy ones they can tear out the socket. The bolt through approach is usually safer. The Socket 478 owners also have a choice between bolting it on and using their retention system. However in this case there are no safety concerns.
Ok, now that that is out of the way you first need to consider a couple of things when selecting a heatsink:
1) Budget
2) What socket is your cpu, see "Sockets:" section above
3) *Applies only to socket A* Do I have the 4 mounting holes on my motherboard
After having answered all of that you need to answer one more question, am I willing to order online?
If you answered no, I recommend you go to your local CompUSA and check out the selection (It has been known to vary by store).
If you answered yes, keep on reading.
The following is an article written by me with the help of the above two people (with the exclusion of the part added by Super Nade). It is therefore my intellectual property and if you wish to copy this onto your webpage please contact me for permission.
Terminology:
Rheostat: Something that controlls the voltage a fan receivs, fan controllers use rheostats, see this excellent guide on how to pick one.
Heatpipes: The topic is too complex for this guide, however here is an excellent link
The most important decision you will have to make when choosing a heatsink:
What is the noise level I am willing to live with, some factors for that are do I live alone, is this computer in my bedroom, and will it run all day and night. Those questions should guide you to selecting whether you want a high performance one or not. If you like to overclock, you will propably need one of the high performance heatsinks and a strong fan, because when overclocking the processor will get hotter (assuming you raise the voltage, even if not better safe then sorry). However just because you chose the high performance route does not mean it can not run quietly (unless you picked a fan labelled as loud) just get a fan controller or Rheostat and quiet it down at night.
Materials: copper and aluminum are the most popular materials in use and copper generally performs better than aluminum. Copper is heavier and more costly however, so many sinks are actually a combination of the two: a "slug" of copper for the cpu core contact area and the rest made of cheaper aluminum. However a pure copper heatsink will perform better then a pure aluminum one (assuming there are no heatpipes being used).
Following is added by Super Nade.
{
If somebody went off into the deep end and wanted to know really why Cu is a better radiator than Al, this rough calculation can be used.
Thermal Conductivity of copper:-
http://www.vcs.ethz.ch/chemglobe/ptoe/_/29.html
[4.01 W/cmK]
Thermal Conductivity of Aluminium:
http://www.vcs.ethz.ch/chemglobe/ptoe/_/13.html
[2.37 W/cmK]
I checked these numbers with the CRC handbook.
My thoughts:-
We know that Planck's radiation law is true. But it is valid in the form seen in textbooks for a black body.So we use Stefan's Law.We are talking about convection/conduction and radiation in our analysis.
Stefan's Law:
P=e x sigma x A x (T^4-t^4)
P---->power radiated
A---->radiating area
sigma----->stefans constant
e---->emissivity {=1 if its a black body}
T/t----->temprature of the radiator/surroundings
Now assuming all things being the same i.e A,T/t, Sigma and convectional losses, the critical parameter here is e.
eCopper=0.119
eAluminium=0.05
http://www.engineeringtoolbox.com/36_447.html
So, how is Aluminum better than copper in this context?
Now, let us analyse the convection/conduction.
As show above the thermal conductivity of Cu > Al. As the thermal conductivity of air is assumed constant for both experiments, Cu wins again!
}
Different heatsink styles:
The regular old heatsink: Usually a square base made out of aluminum or copper and then fins attached on top. The higher quality blocks have many thin fins, so they have the most surface area they also require a stronger fan to run. The lower end blocks tend to have thick fins with a good amount of space in between. This requires a less powerful fan and are cheaper to make.
The tower heatsink: A heatsink, has a square base like a normal one. However then there are copper heatpipes going out to a rather large tower of copper or aluminum. These heatsinks are usually large enough to hold two fans. However they do not outperform a quality "normal" heatsink running on one fan. Also, the same fin density principle applies here see above.
Sockets:
Socket 478: This is the socket the new pentium 4's use, the most common.
Socket A (462): Athlons/Durons/Athlon XP's the main AMD line at this point
Socket 754: AMD Athlon 64's this socket will not be updated for too much longer
Socket 939: The new Athlon 64's will be out for this socket
Socket 940: AMD Athlon 64 FX's and Opterons are on this socket
Mounting:
On all except two socket, there is only one way to mount a heatsink, that is usually through bolting it on there. The Socket A users have a choice between bolting it on and using the clips. The clips are fine for light heatsinks, but on heavy ones they can tear out the socket. The bolt through approach is usually safer. The Socket 478 owners also have a choice between bolting it on and using their retention system. However in this case there are no safety concerns.
Ok, now that that is out of the way you first need to consider a couple of things when selecting a heatsink:
1) Budget
2) What socket is your cpu, see "Sockets:" section above
3) *Applies only to socket A* Do I have the 4 mounting holes on my motherboard
After having answered all of that you need to answer one more question, am I willing to order online?
If you answered no, I recommend you go to your local CompUSA and check out the selection (It has been known to vary by store).
If you answered yes, keep on reading.
Last edited:
