When Should You Replace Thermal Paste in CPU Heat Sink?

The processors of all kinds in your computer (CPU, GPU or the newer APU) get heated up after some time of use. They must be cooled to prevent electronic and mechanical damage and failure. In order to keep them cool, a heat sink is installed over the processors. The heat sink is metallic – a good conductor of heat, and therefore the heat from the processors flows into the heat sink. The heat from the heatsink is later dissipated into the atmosphere using a simple fan that blows air over the heat sink fins. But to make sure that the heatsink collects all the heat from the processors it is attached to the processor surface using a special thermally conductive compound called thermal paste (also called thermal compound or thermal grease).

The thermal paste, like any other chemical, becomes weak and less efficient over a period of time and needs to be replaced. But how should one find out when is the right time to replace the thermal compound. Here are some of the pointers that can be used to determine that the time to replace the thermal compound has arrived.

Replacing Thermal Paste

  1. After every two years of continued computer usage, especially if you use your computer everyday in a non-air-conditioned environment for 7-8 or more hours.
  2. If you accidentally shake the processor heat sink while cleaning the interior of your computer cabinet. The shaking of the heat sink could let some air slip into the surface between the processor surface and the heatsink. This small amount of air can absorb and accumulate the heat and damage the processor.
  3. If your PC is getting intermittent lags and the processor temperatures are rising up to higher levels than expected. You can use the free HWiNFO tool to find out the temperatures of your CPU, GPU, hard disks and other components. Typically, if the temperatures of the processor are reaching higher than 50 degree Celsius, then you should quickly clean all the dust, change the thermal paste, and make sure that air flow is not being obstructed – perhaps install a new cooling fan.Replacing Thermal Paste
  4. Every time you remove the heat sink to clean the dust and other type of dirt that piles up inside the heat sink. Some people think that they can re-use the old thermal paste, but it is a bad idea and does not work at all.

Conclusion: Changing the thermal paste in your processor’s heatsink can give it a new life. But you should not unnecessarily replace the thermal paste too often. Instead you should replace the thermal compound only when a significant performance gain is expected.