Why Western Digital completely embarrassed Seagate in the 2025 Backblaze reliability report
Backblaze is one of the world’s largest cloud storage companies and the publisher of an annual hard drive statistics report it has been providing since 2013. The company recently released its 2025 report, so let’s dive into the data and see which drives were the most reliable and which earned the dubious honor of being the least reliable.
Overall, Western Digital had the most reliable hard drives in 2025
Technically, WD was also the least reliable supplier
Looking at the overall numbers, Western Digital (WDC) had the most reliable hard drives of 2025. Of the five models found in Backblaze’s data centers, only one had a failure rate above 1%: the WUH721816ALE6L0 16TB, at 1.97%. Overall, WDC drives had a failure rate of just 0.86%, which is impressive considering they make up nearly a quarter of Backblaze’s fleet.
WDC was followed by Toshiba, with an average failure rate of 1.86%; HTPS, at 2.26%; and Seagate, at 2.41%. While these numbers were great across the board, Toshiba was arguably the best in terms of scale, supplying over a third of the drives used by Backblaze. Seagate drives make up a similar share of the fleet (33.59% vs. Toshiba’s 33.46%), making HGST the worst performer of 2025, as it barely edges out Seagate despite only accounting for 8.04% of Backblaze’s total drives. Since HGST (formerly Hitachi) is owned by Western Digital, we could say that Western Digital was both the best and worst performer in Backblaze’s data centers in 2025.
No drives reached zero failure rate
Only 12 models had a failure rate below 1%
When looking at annual statistics, not a single hard drive model has managed to achieve the 0% failure rate, which is the crowning achievement. Some were very close, but everyone had at least one failure.
Looking at the absolute number of failures, only one out of 466 Seagate ST16000NM002J 16TB drives failed throughout 2025. However, given the tiny sample size, I don’t think this deserves praise. The same can be said for the WDC WUH722626ALE6L4 26TB, which has also only had one failure, but only 1,201 drives are in operation and the model has only been in use for a quarter.
Only 12 models in total managed to stay below a 1% failure rate, with WDC again coming out on top. Four of its five models remained below 1%, which is impressive considering there are 31 models in total and WDC drives accounted for a quarter of all models in the “below 1%” group.
The dubious honor of least reliable drive of 2025 goes to the Toshiba MG08ACA16TEY 16TB, which has a failure rate of 6.30%, the only drive to cross the 6% threshold. However, this result comes with a major caveat: the drive saw an apparent failure rate of 16.95% in Q3 2025. This spike was due to Backblaze working with Toshiba to deploy firmware updates on this model, which required many drives to be taken offline, which showed up in the data as failures. As shown below, reliability stabilized over the next quarter and the drive has historically been quite reliable. So let’s take a look at the second worst performer.
This would be the Seagate ST10000NM0086 10TB, which had an annual failure rate of 5.66%. This time it’s probably due to its age: it’s over seven years old and has a relatively small number of units in service (1,044), with each failure contributing significantly to the total rate. In other words, the disk isn’t bad, it’s just old, but still useful.
The most reliable hard drive model of 2025 was also made by Western Digital
Closely followed by a Seagate model
Taking into account both the number of drives in use and their failure rates, the most reliable drive of 2025 was the WDC WUH722222ALE6L4 22TB. There are 44,577 units in use in Backblaze’s data centers, with an annual failure rate of just 0.47%. Talk about reliability.
The WDC model is closely followed by the Seagate ST16000NM001G 16TB, which has a failure rate of 0.54% from a massive sample of 34,563 units currently in service.
Hard drives were more reliable in 2025 than in previous years
The annual failure rate (AFR) for 2025 was only 1.36%, a notable improvement from the previous two years. For example, the AFR stood at 1.57% in 2024 and a relatively high 1.70% in 2023. That said, looking at historical trends, the 2025 figure is roughly in line with the lifetime AFR of 1.30%.
This tells us that enterprise storage drives are extremely reliable. Sure, some models perform worse than others and some providers have fairly high failure rates (HGST, for example), relatively speaking, but when you look at the big picture, the overall level of reliability is striking.
The biggest winner of 2025, at least according to Backblaze data, was Western Digital. Not only was it crowned the most reliable vendor overall, but it also produced the most reliable hard drive of the year. A clean slate.
- Storage capacity
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2 to 26 TB
- Workload
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550 TB/year
Western Digital’s Red Pro NAS hard drives are available in sizes ranging from 2TB to 26TB.
