Backblaze has released its hard drive statistics for 2016, and the findings indicate that reliability is improving.

Three hard drive models survived all of 2016 at the cloud storage and backup services provider without a single failure, an 8TB drive from HGST (HUH728080ALE600) and a 4TB drive from Toshiba (MD04ABA400V). An 8TB model from Seagate (ST8000NM0055) also survived 2016, but it was deployed in November the company said.

Andy Klein, director of Product Marketing at Backblaze, also noted that those drives were deployed in relatively smaller numbers (45 HGST, 146 Toshiba and 60 Seagate) in a Jan. 31 announcement. The company’s data suggest that as drive counts rise into the hundreds and thousands of units and the drives are put through their paces, failures appear inevitable.

For example, the most widely-deployed hard drive in Backblaze’s arsenal is the 4TB Seagate ST4000DM000 with a total of 34,738 units. With an average age of nearly 21 months, this model suffered a failure rate of 2.77 percent, or 938 drives. Among the 9,407 HGST HMS5C4040BLE640 4TB drives spinning away at the company’s data center (average age of over 15 months), 34 have called it quits, a failure rate of 0.51 percent.

“The total number of failed drives was 1,225 for the year. That’s 3.36 drive failures per day or about 5 drives per workday, a very manageable workload,” stated Klein. In 2016, Backblaze had a total of 71,939 hard drives in operation.

In general, Backblaze’s suggests that data hard drive vendors are making hardier drives these days. “The overall hard drive failure rate for 2016 was 1.95 percent. That’s down from 2.47 percent in 2015 and well below the 6.39 percent failure rate for 2014,” added Klein.

In terms of capacity, and irrespective of vendor, 3TB drives fared well with a failure rate of 1.4 percent in 2016, followed by 8TB drives (1.6 percent) and 6TB drives (1.76 percent). 5TB and 4TB drives exhibited failure rates of over 2 percent, though it should be noted that there is a lot of variability in the number of each type deployed at Backblaze.

With that caveat in mind, HGST drives outlasted most makes with a failure rate of just 0.6 percent. Toshiba took second place with 1.27 percent and Seagate took third with 2.65 percent. Western Digital trailed with a failure rate of 3.88 percent.