Backblaze, a backup service, used 41,213 hard drives to store customer’s data. The drives that were most reliable, they say, were four-terabyte capacity units from “HGST,” which was formerly a division of Hitachi. Only one percent of their drives failed. Western Digital, which recently bought the Hitachi unit, came in second and Seagate third.
Seagate was third largely because of its three-terabyte drives, which had a 40 percent failure rate — huge. Its larger and smaller drives, however, performed much better.