Backblaze Publishes 2015 Hard Drive Reliability Stats
Cloud backup service Backblaze has once again shared its internal statistics on the reliability of hard drives in its data center. In the cumulative failure data dating back to April 2013, Western Digital’s drives had the highest rate of failure, at around 7 percent, while HGST’s had the lowest, at just over 1 percent. However, when looking at 4 TB drives, which now comprise 75 percent of Backblaze’s drives, Seagate, Toshiba, and Western Digital hover around a 3 percent failure rate. HGST 4 TB drives are again the best, with a failure rate under 1 percent, but Backblaze stopped buying those drives because they were replaced with more expensive models.
I have to mention this every time Backblaze updates its stats. This information is useful but must be viewed in context. Backblaze buys large quantities of mostly low-cost drives, and their use case has different emphases from the individual user shopping for a reliable hard drive for their own computer. Generally, I pay attention to their failure rates but regard the positive reliability data as incomplete. For instance, I have found WD Black drives to be very reliable, have a five year warranty, and aren't too expensive, while WD Blue I avoid like the plague. Backblaze data doesn't usually include the Black line.