This photograph was composed less than 15 minutes ago to portray the heat sink which has now been installed on the Broadcom SOC integrated circuit
In a passive set up the heat sink does not do much, the temperature drops just with a couple of degrees and the order of two to 3° C
With a fan spinning air on the heat sink the temperature drop is significant
From my experience with electronics I know that heat sinks designed for Passive cooling have longer fins. For example the heat sink that I used to repair my National monochromatic television 12" when I was a kid, had very long fins and the heat sink was about as tall as my thumb {8.5cm}
That analog Integrated Circuit controlled almost everything in the television, which made the circuit board quite Compact and easily maintainable
Corrections made with the compliments of @AnachronistJohn I entangled the SOC with the WiFI IC since it's from Broadcom, which also makes network ICs