A heat sink is a passive cooling component, usually made of aluminium or copper, that conducts heat away from a chip and releases it into the air through a large fin surface. A fan is often added to push air across the fins.
Why it matters
Processors, graphics chips, voltage regulators, and SSD controllers all turn electricity into heat. If that heat is not removed, the chip lowers its speed to protect itself, a behaviour known as thermal throttling, or in the worst case shuts down. Copper conducts heat better than aluminium but is heavier and more expensive, so many coolers use a copper base or heat pipes with aluminium fins.
Heat pipes contain a small amount of liquid that evaporates at the hot end and condenses at the cool end, moving heat quickly along the cooler.
Example
A small passive heat sink on a Raspberry Pi can keep a light workload cool, while a tower cooler with several heat pipes and a fan is used for a desktop CPU with a high power rating. Case airflow matters as much as the heat sink: hot air must have somewhere to go.
Common mistakes
- Skipping thermal paste or leaving the plastic film on the cooler base.
- Mounting with uneven pressure.
- Letting dust clog the fins, which quietly raises temperatures.
- Choosing a cooler too tall for the case.
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