O Google realmente fez um grande estudo sobre isso. Está disponível aqui:
Eduardo Pinheiro, Wolf-Dietrich Weber and Luiz Andre Barroso
Failure Trends in a Large Disk Drive Population
Deste relatório:
One of our key findings has been the lack of a consistent pattern of higher failure rates for higher temperature drives or for those drives at higher utilization levels. Such correlations have been repeatedly highlighted by previous studies, but we are unable to confirm them by observing our population.
[…]
Our results confirm the findings of previous smaller population studies that suggest that some of the SMART parameters are well-correlated with higher failure probabilities. We find, for example, that after their first scan error, drives are 39 times more likely to fail within 60 days than drives with no such errors. First errors in reallocations, offline reallocations, and probational counts are also strongly correlated to higher failure probabilities.
A maior coisa a fazer, na verdade, é manter essas unidades legais. O calor faz muito mais dano do que apenas ler / escrever.