Look at this hard drive data: Sales are way down but reliability is way up

The latest stats from Backblaze, running over 140,000 drives in its data centers, point out some stars -- and some dogs -- among 4TB to 16TB drives.

The Q2 numbers reached a heartening milestone: The lowest-ever Annual Failure Rate (AFR) -- 0.81% -- since 2013, and it's the first time the AFR has been under 1% in any quarter.

You can read the entire results at Backblaze, but here are the important takeaways.

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HGST -- now a division of Western Digital -- continues to have the most reliable drives, with a cumulative AFR of just 0.47%.

Toshiba comes in second at 0.98%.

Seagate brings up the rear this quarter at 2.05% AFR.

WDC (Western Digital) hard drives aren't in the listing. Backblaze doesn't say so, but I suspect it stopped buying WDC drives because it had, far and away, the highest AFR (almost 4%) at the beginning of last year. It brought in some newer models for testing, so maybe it'll be back in a later quarter's results.

Capacity

It's reasonable to assume that high-capacity drives, being newer, would be less reliable. But that's not always the case.

HGST AFRs are consistent. The 4TB and 12TB (ALE600) drives have equally low 0.44% AFRs. Its N604 12TB model has a slightly higher AFR at 0.48%.

Seagate has two 12TB drive models, and one has half the AFR of the other. Their 10TB is the most reliable (0.74%) and the 16TB drive its least (3.49%) of all the tested drives.

Toshiba's 4TB drive is one of the most reliable, while its 14TB drive is only slightly less so, and is on a par with the better Seagate 12TB drive at 1.06% AFR.

The take

Use this data with an appreciation for its limits. Backblaze often has thousands of each drive and a resilient infrastructure that automagically handles drive failures.

Even if you buy the most reliable 12TB drive, if it fails -- and it might -- the stats won't matter. Be sure to back up.

Disk drives are modern miracles of precision engineering and manufacturing. Even the worst of the drives today is way better than drives of 20 years ago and a lot less costly.

And thanks to Backblaze for breaking the industry code of silence on drive reliability.

Comments welcome. I have 10-year-old hard drives still chugging along. What's your oldest drive?