Quote:
Originally posted by maskedgeek
yes i did see your post, and i kinda responded to a few at once... yes its pretty much 2x more conductive...in theory pretty much, but when it comes to real life situations of watercooling computers its not exactly like that
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It's statements like your last one that bring exasperation to engineers. Metals have no brain. They do not know if they are cooling a CPU, being used to conduct electricity, or even sitting in the ground in varied states. Pure copper will
always behave the same in conduction. Pure aluminum will
always behave the same in conduction.
Pure copper will always have nearly twice the heat conductivity coefficient of aluminum. This means that in equal shapes, copper will always have slightly more than 1/2 the temperature differential as aluminum when conducting heat through the same pathway.
Why you will not see a precise difference for a given power is that the flow pathway of the heat will not be precisely the same for the two materials. Copper will cause heat to spread over a larger area than aluminum, all other things being constant. For this reason, you will frequently see differentials less than 1/2 for copper versus aluminum.
In air cooled heat sinks, you'll actually find that aluminum does a better job as fins/pins. Not because of some absurd idea that "aluminum gets rid of heat better than copper". It's simply a question of surface area. For a given
weight, aluminum has far more surface area and gains the advantage in convection. I'll guarantee you that less than 5% of the people that consider themselves cooling gurus really understand this basic priciple.
In water cooled blocks, this advantage is largely muted because of the inherently higher convection coefficients of water. This puts an even higher premium on a material's conductivity.
Now, as BigBen2k and BillA noted, you can do just fine with aluminum,
but you'll never do as well as copper. I'll guarantee that you'll tend to see a variation of 2-5°C for most blocks and power levels if you made the blocks from both materials. Is the extra cost of the raw material and machining difficulty worth 2-5°C? Not for most people, but that doesn't change the fact that it exists.
What you see as an irate attitude towards your questions folks like BillA see as ignorance in search of an easy answer. All the answers you seek are available, but it doesn't do a whole lotta good to simply tell you the answers. Unless you
understand why things are the way they are, you doom yourself to blindly proceeding randomly. You may make a few different blocks with some performing better than others and have no idea why. Rather than pop in and ask for all the answers, invest some time to search for those answers on your own, both through hands on research and by reading. And I got news for ya, if you think you're going to find good information cruising forums you are sadly mistaken. There are plenty of very smart people that hang here and elsewhere, but they're outnumbered by morons that spout conjecture without proof. Again, unless you understand the real issues, you have no way to separate the good stuff from the garbage.
OK, I'll get off my soapbox now. . .