Google has a huge hard-drive farm for which they frequently take (and store) state-of-health information. Researchers decided to use this database to analyze the key factors in hard drive failures. Surprisingly, they found there was “very little correlation” between hard drive failure and elevated temperature or high activity. They also determined that certain SMART parameters were good predictors of hard drive failure, but that the opposite was not true—many hard drives failed without a consistent pattern of SMART parameters. Of most interest to me was the fact that certain models and manufacturers had a higher failure rate, but unfortunately Google did not publish the specific names. The full study (13 page PDF file) is available here.
Thanks to Josh for suggesting this topic.