Probably just more sensitive to vibration in long term use. 40% AFR in normal conditions would be insane, and I doubt we'd need Backblaze to point it out.
I have six ST3000DM001's and seven ST31500341AS's, all with about 2 years on the clock (~20,000 power-on hours). With 40% and 25% AFR's respectively, the odds of all thirteen surviving are:
I have six ST3000DM001's and seven ST31500341AS's, all with about 2 years on the clock (~20,000 power-on hours). With 40% and 25% AFR's respectively, the odds of all thirteen surviving are:
1 / ((0.6 12) * (0.75 14)) = 1 in 25,782.
I doubt I'm that lucky.