Weight, life, cost, these are not to mention, let's just talk about the heat dissipation capacity, and make a simple comparison of some physical properties of the two materials: pure copper and pure aluminum:
Everyone thinks that copper has a strong thermal conductivity because the thermal conductivity of copper is much higher than that of aluminum (here refers to pure copper and pure aluminum). This is indeed what I have learned in middle school. However, the heat dissipation capacity of a radiator is not only related to the thermal conductivity of the material, but also related to the heat dissipation area, the shape of the radiator, and the air flow.
Looking at the last two parameters, if you look at the number of specific heat capacity, you will definitely say, wow, the specific heat capacity of copper is smaller, its temperature rises faster, and it is not easier to dissipate heat (the law of thermodynamics, the greater the temperature gradient, the heat transfer The sooner), it seems to be correct, but...you have to look at their density.
The density of copper is 3.3 times that of aluminum. The radiator is a size-sensitive product and cannot be made infinitely large. Under the same size, is the heat capacity of copper or aluminum small? Let's do a simple calculation.
Assuming they are all materials of the size of one cubic centimeter, the weight of copper is 8.9 grams. To make it rise 1K, it needs 3.4KJ of heat. Under this size, the weight of aluminum is 2.7 grams. To make it rise 1K, the heat required is 2.4KJ. In other words, the heat capacity of aluminum per unit volume is only 70% of copper, and its heat dissipation is faster.
Therefore, although the thermal conductivity of copper is higher than that of aluminum, and the resistance to heat transfer from the CPU to the environment is small, it has a larger heat capacity and a slower temperature rise under the same volume, so that the temperature gradient is small, and the comprehensive heat transfer capacity is lower. Not necessarily better than aluminum.