Photo by Backblaze
Backblaze Releases Q3 2018 Hard Drive Reliability Numbers
Online backup provider Backblaze (a TidBITS sponsor) has been publishing hard drive reliability statistics for years, and the company just published numbers for Q3 2018 across an installed base of 97,600 drives. Backblaze has now abandoned 3 TB drives for higher capacity ones—up to 12 TB—and overall reliability numbers look excellent, with failure rates around 2% or less. Notably, the Seagate 8 TB and 12 TB drives are showing failure rates around 1%. The only concerning data point comes from a 6 TB Western Digital drive, which had a failure rate over 4%. To be fair, that’s within a very small sample size of only 383 drives (compared to the 25,101 Seagate 12 TB drives that Backblaze has). If you’re looking for a new external hard drive, we recommend looking at models that have fared well at scale for Backblaze.
The TidBITS article says, “Notably, the Seagate 8 TB and 12 TB drives are showing failure rates around 1%.” This is useful information, but it might give a misleading impression of the reliability figures relative to other manufacturers. The five HGST models in the chart have failure rates of 0.0, 0.0, 0.27, 0.34, and 0.38%. While most of these have a much smaller sample size than the two Seagate models that you highlighted, the HGST 4TB model with the 0.27% failure rate has the third highest number of drive days of all those in the chart. The Seagate 4TB model, with a similar number of drive days, has a 2.28% failure rate.
Over the years, HGST has had an average failure rate below that of Seagate in the Backblaze statistics. I have no connection with HGST nor with Backblaze, except as a satisfied customer.
Like all our ExtraBITS, our goal is for readers to go read the original post—we’re just summarizing and calling out enticing bits.
The HGST failure rates are indeed very good, but with much smaller sample sizes, it’s hard to draw a specific conclusion.
Id love to attach two of these 12TB drives onto my Mac mini… what are the favoured enclosures these days?
I generally use OWC enclosures, but don’t have much to compare against because of that.