Overclocking stresses the need for adequate cooling even further. The relatively low premium to be paid for a good cooling device is in no relation to the gain that can be achieved, both with regard to reliability and logevity of the components as well as to unlock the maximum performance of the system via overclocking. Some theoretical background as well as fantasy and minor skills with hacksaw and file are no prerequisite but come in handy to mount a massive combo on a clearance restricted mainboard. Thermaltake have built themselves a reputation for supplying those round heat sinks with fans integrated instead of sitting on top, so have some other companies. That is, the principle of any efficient cooling is to move the heat away from its source as quickly and efficiently as possible.
Capacitance is the product of the materials capacitance constant and the mass used.
If the mass in the area of contact is kept to a minimum whereas more mass is accumulated in the fins, the latter will act like a sponge for excess heat. Adequate airflow around these fins will allow for heat dissipation. The shape of the fins is important since it determines surface velocity and aids in preventing turbulences. The possibly best shape for fins is an elongated drop shape that, similar to an airplane s wing, provides high surface velocity with good laminar flow and little turbulences. According to all these specifications, the best heatsink would be one that provides radial airflow over an empty center with drop-shaped fins flanking the surround.