There are many microscopic pits on the contact surface of the CPU and the heat sink, and the thermal conductive silicone grease contains the main thermally conductive component materials, including various chemical auxiliaries that play a role in even flow distribution and adhesion. Theoretically, the more microscopic and small, the more it can fill the contact surface of both, the more it can improve the thermal performance.
However, if I talk about a typical CPU incident, I believe we all have a slight understanding of it. A few years ago, Intel's CPU in Ivy Bridge architecture had a much higher temperature than Sandy Bridge when it was overclocked, because the previous CPU top cover package used a brazing process, while the later one used ordinary silicone grease, which was also a hot topic in the DIY world. This is also the reason why the DIY community has been talking about the "CPU open cover" incident.
There will be different performance decline some even two or three months later, the temperature soared up again. I believe that the dismantling or repair of the computer, the dismantling of a good CPU cooler know that some years later, the CPU thermal grease, have become dry and hard. In fact, this is also related to the process is very much, like the production process of thermal conductivity materials, chemical auxiliaries evaporated dry, etc.. From a practical point of view, I personally feel that if the performance period reaches 1.5 to 2 years, the performance is slowly declining, or acceptable, but if only three to five months, the performance drops steeply, it is unacceptable, three to five months to remove the computer to replace the silicone grease.
