Data Recovery Digest

A new study by Backblaze has confirmed what most of us already know – solid-state drives (SSDs) are more reliable than traditional hard disk drives (HDDs). However, you might be surprised at how small the difference actually is. Per their report, modern SSDs have an annualized failure rate (AFR) of 0.98%, whereas HDDs have an AFR of 1.64%. For those who are mathematically inclined, this only represents a difference of 0.66% -- but there’s a little more to it than just that.

Who is Backblaze?

For starters, Backblaze is an online backup and storage service provider. It’s generally meant as a highly intuitive, easy-to-use platform that takes all the hassle out of backing up your data. However, its limited controls tend to leave tech-savvy customers wanting more from the service. Regardless of your feelings, it’s safe to say that the company knows a thing or two about data backup – they have been around since 2007, after all.

What Drives Were Tested?

All of the SSDs that were tested were actually used as boot drives in Backblaze’s own storage servers. In total, there were 13 different SSD models – many of which are classified as consumer-grade drives. Since many of these drives are purchasable right off the shelf, their analysis provides an pretty accurate picture of the current state of SSDs – even if they were working with a rather limited sample size.

A Limited Sample

Despite their findings, Backblaze’s report only analyzed 2,906 SSDs in total. It’s certainly a small sample size, but the data still can’t be dismissed. The team at Backblaze included this caveat in their initial report, even commenting on the fact that it was so limited. However, they do plan on increasing the scale of their analyses in the future, which will likely give us a better picture of the overall performance of SSDs versus HDDs.

Nonetheless, seven of the 13 models tested experienced no failures whatsoever. Of those seven models, six of them were in operation for less than 10,000 drive days, so they didn’t really have enough data on the AFR of those models. One model in particular, an SSD manufactured by Dell, actually had more than 100,000 drive days – and the AFR on that specific drive was exceptional. However, it’s important to note that this was an M.2 SSD on a PCIe card, and this setup is generally meant for use in large-scale servers. However, three other drives tested also had more than 100,000 drive days – providing more than enough data for a reliable analysis.

Issues with S.M.A.R.T.

Backblaze’s latest test also uncovered some issues with the S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology) used in many modern SSDs. Because manufacturers don’t exactly agree on some of the technical terms used in the S.M.A.R.T. protocol, consumers can’t really rely on the data derived from S.M.A.R.T. to make these drives on their own.

Andy Klein, the author of Backblaze’s report, was noted as saying: “Terms like wear leveling, endurance, lifetime used, life used, LBAs [Logical Block Address] written, LBAs read, and so on are used inconsistently between manufacturers, often using different SMART attributes, and sometimes they are not recorded at all.”