Thermal paste, also sometimes referred to as thermal compound or thermal grease, is a substance that is often used as an interface between heat sources like high-powered semiconductor devices and heat sinks, to eliminate air gaps from the area of the interface so as to maximise heat transfer and dissipation.
The question that many people are often left pondering however is how often thermal paste needs to be changed and the question is not as easy to answer as you might think with many different opinions regarding the paste’s lifespan.
The thermal paste brand that has been used can be a major factor in their longevity, in addition to other considerations, and it is a good idea to look for other people’s experiences in regards to the durability of their thermal paste.
When to change thermal paste
Many people only think to ask how often they need to change thermal paste when they have already begun to experience difficulties but the good news is there are a few signs to take note of that indicate that the reapplication of thermal paste may be due.
One of the simplest is that you are upgrading other aspects like the CPU or the CPU cooler. Thermal paste cannot be reused which means that it needs to be reapplied every time that the CPU cooler is removed from the CPU.
Prior to the reapplication of thermal paste the old thermal paste should be cleaned out, with no trace of it remaining.
The thermal paste will need to be changed as air bubbles could be left by the old thermal paste, which might also have mostly already dried up. If the texture of the old thermal paste is very flaky then it should be cleaned out and replaced.
Another sign that can be a warning sign of a change to your thermal paste is if the temperature of your CPU is rising to alarming levels. High CPU temperatures can cause a number of different problems but a change should be observable when the same application is being used.
Issues that can affect thermal paste
Thermal paste is used for the purpose of drawing out the CPU’s heat as quickly as possible. As air is not a good heat conductor an air cooler is insufficient for the maintaining of safe temperature levels, which is why thermal paste is required.
The application of thermal paste will see an immediate reduction in temperatures even before the cooler starts working though the higher temperatures are the faster the thermal paste will dry up. This is one of the reasons why there is such inconsistency in the reporting of the longevity of thermal paste.
Some sources say that thermal paste has a lifespan of around two years while others have found it can last up to as long as a decade without the need for reapplication.
The mixture that makes up a particular thermal paste can also be a factor. For computers the best thermal paste is made from 100% liquid metal. All brands are mixed differently and come with different thermal conductivity.