Back in January, online backup provider Backblaze published reliability statistics on over 25,000 mechanical hard drives deployed in its storage servers. In that setting, Hitachi's hard drives proved the most reliable, followed by units from WD. Seagate's didn't fare as well, with most exhibiting much higher failure rates than their rivals.
Since that initial data dump, Backblaze has added nearly 10,000 drives to its stable. The firm has also posted a fresh batch of results detailing failure rates through June—and a handy graph that compares the new data to the numbers from January. (Ignore the mention of September in the graph; it refers to the date the blog post was published.)
Although little has changed for most of the drives, there are a couple of exceptions. The annual failure rate for 3TB Seagate units has risen by a notable margin. Backblaze attributes most of the increase to the Barracuda 7200.14, whose death rate is twice that of the equivalent Barracuda XT. The newer Desktop HDD.15 4TB is faring much better than its predecessors, though it hasn't been in service for nearly as long.
WD's 3TB drives are failing more frequently, too. Most of those are from the NAS-oriented Red family, whose 3TB incarnation has loads of negative Newegg reviews complaining about poor reliability.
The Hitachi HDDs continue to have the lowest failure rates regardless of the capacity or spindle speed. However, keep in mind that Backblaze's data center environment—and the company's propensity for harvesting drives from external enclosures—isn't typical of normal desktop use. It's great to have model-specific reliability data on this kind of scale, but the results don't necessarily predict which drives will be more dependable in the average desktop.