Which brand of hard disk is most reliable?

Backblaze reveals more statistics about hard drives, comparing reliability by manufacturer

Nicole Kobie
21 Jan 2014

Cloud storage firm Backblaze has released data on the ultimate hard drive battle: which hardware lasts longest under heavy-use conditions?

The company uses consumer-grade drives in its storage arrays, and has previously published data showing that these drives are just as hard-wearing as more expensive enterprise-level equipment. It's also calculated the average life-span of a hard drive.

Now, the company has revealed which brand of drives has the fewest failures and lasts the longest: Hitachi.

"If the price were right, we would be buying nothing but Hitachi drives," wrote Backblaze engineer Brian Beach on the company blog. "They have been rock solid, and have had a remarkably low failure rate."

Find out more

For the full breakdown by model, take a look at Backblaze's blog post.

For each of the tested capacities, Hitachi's failure rate - the average proportion of drives failing each year - was below 2%, while Western Digital's hovered about the 3% mark. Seagate ranged between 4% and 14%.

As well as the highest overall reliability, Hitachi disks also posted the lowest level of "trouble" - when a drive has issues, but doesn't fail completely. While automated recovery can often fix the problem, drives in a "trouble" state sometimes need to be removed and repaired, leading to downtime.

Each of the three manufacturers posted uptime of more than 99%, but again Hitachi came out on top, with 99.99% "active" time, versus 99.83% for Western Digital and 99.72% for Seagate.

Caveats to the figures

The company doesn't use enough Toshiba or Samsung drives to include them in its figures, so the comparison is limited to Hitachi, Seagate and Western Digital. And Seagate's third-place ranking doesn't mean all Seagate drives are troubled: Beach called the 1.5TB versions "solid workhorses", despite observing lower reliability levels for other models, notably the Barracuda Green and the Barracuda 7200.

"The good pricing on Seagate drives along with the consistent, but not great, performance is why we have a lot of them," he said.

Beach also noted that Hitachi was bought out by Western Digital a year and a half ago. "Will Hitachi drives continue their excellent performance? Will Western Digital bring some of the Hitachi reliability into their consumer-grade drives?" For that, Backblaze doesn't yet have any answers.

Green troubles

Finally, Beach revealed that low-power drives are more likely to fail - but that's specifically in his company's heavy-use scenario.

"The drives that just don’t work in our environment are Western Digital Green 3TB drives and Seagate LP (low power) 2TB drives," he wrote. "Both of these drives start accumulating errors as soon as they are put into production."

"We think this is related to vibration. These drives are designed to be energy-efficient, and spin down aggressively when not in use," he added. "In the Backblaze environment, they spin down frequently, and then spin right back up. We think that this causes a lot of wear on the drive."

Beach acknowledged that Backblaze uses its hard drives more intensely than is common for consumer drives, and stressed that the company's experiences don't mean low-power drives aren't worth buying. "It wouldn’t be fair to call a drive 'bad' if it’s just not suited for the environment it’s put into," he said.

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