Ars Technica heeft een paar pagina's tekst vol weten te schrijven over heatsinks. Alle basis informatie over heatsinks komt aan de orde: heatsink & fan design, koelprut, lapping en hoeveel beter een echte heatsink is boven de standaard Intel fan:
Meet Heat. AKA the enemy. Without delving into the fine distinctions made by physics between molecular movement, energy transference, and whatnot, let's just focus on what's clear: heat is "generated" by CPUs and other electronics, and when accumulated, it can cause damage. We want to get it away from our electronics as quickly as possible. Traditionally speaking, heat can be dissipated in a variety of ways, of which only two are relevant to this discussion. Interestingly, these two methods literally "encompass" the topic of heatsinks.
Now, the most important factor in a heatsink is, naturally, its ability to dissipate the largest amount of heat in the shortest amount of time. This ability depends on a number of factors. First is material. The vast majority of heatsinks are made out of aluminum. Aluminum is an excellent conductor of heat, and relatively cheap. 'Conduction' is the primary method by which heat will be removed from your CPU, or other cooled device. Roughly speaking, conduction can be understood as the transfer of molecular kinetic energy between solids. If you stick your finger on a hot boilerplate, the extremely exited molecules in the boilerplate will collide with the molecules in your finger, gettin' them all excited as well, and hence displacing a bit of the energy. When choosing a conductor, we ideally want to go for something that can "absorb" a lot of heat, quickly. This is why heatsinks are made of metal, and not cotton ;-)