For the wear and tear of thermal cycling to pile up, it's not required to have reboots or shutdowns. All it takes is to have temperature fluctuations that in tu

For the wear and tear of thermal cycling to pile up, it's not required to have reboots or shutdowns. All it takes is to have temperature fluctuations that in turn developt stress fluctuations, which induce fatigue wear on materials. Low amplitude cycles are better and less damaging than high amplitude cycles, but the damage is still there building up. To put things in perspective, not so long ago it was believed that below a certain stress delta some materials were immune to fatigue and practically eternal. However it was soon apparent that that belief was not factual, and a phenomenon labelled very high cycle fatigue started to become a research topic. This type of fatigue is characterized by cracks being induced even at very low stress levels due to defects such as impurities and even crystal size in metal matrices.