While all of these drives passed through formatting and load testing without incident, it is a little too early to reach any conclusions. With a combined 13,000 drive days in operation, they’ve had zero failures. The 10- and 12 TB drive models are new.The average age of all the other drive models is less than 4 years, with nearly 80% of all of the drives being less than 3 years old. Only the 4 TB HGST drives (model: HDS5C4040ALE630) have an average age over 4 years - 51.3 months to be precise. There are several factors that contribute to this, but one that stands out is the average age of the hard drives in use. The hard drive failure rate for the quarter was 1.84%, our lowest quarterly rate ever. The latest lifetime hard drive failure data published by Backblaze, which covers the period from April 2013 until June 2019, showed that their 8TB and 10TB hard.The drives are new, though, so require more long-term stressing to provide an accurate picture of their reliability. Saying that, close to 80% of Backblaze’s HDDs are less than three years old. For our evaluation we remove from consideration those drives which were used for testing purposes and those drive models for which we did not have at least 45 drives (read why after the chart). This is borne out by Backblaze’s Q3 review, which reports zero failures for its new 1,240 10TB and 12TB drives. Hard Drive Reliability Statistics for Q4 2017 At the end of Q4 2017 Backblaze was monitoring 91,305 hard drives used to store data. Although hard drive sales are in decline, new HDDs are becoming more reliable every day. Notably, the company now includes 10TB and 12TB drives for the first time. Data storage provider Backblaze unveiled its latest HDD failure stats for 2017’s third quarter. Andy Klein, the report's author, says that Backblaze has been collecting data since 2013 and has tabulated 88 million statistical records pertaining to 93,000 hard drives.