Are Hard Drives Getting Better? Let’s Revisit the Bathtub Curve

I always love Backblaze's analysis. It's how I learned I wasn't special for having those notorious 4TB Seagate drives (I want to say DM003) shit the bed in short order.

Increased longevity is undoubtedly a plus; however, whether doing a RAID rebuild or just being out a 24TB drive (hopefully, you've got a backup), that's a lot of time and effort to get back to square one.

If you’ve hung around Backblaze for a while (and especially if you’re a Drive Stats fan), you may have heard us talking about the bathtub curve. In Drive Failure Over Time: The Bathtub Curve Is Leaking, we challenged one of reliability engineering’s oldest ideas—the notion that drive failures trace a predictable U-shaped curve over time.

But, the data didn’t agree. Our fleet showed dips, spikes, and plateaus that refused to behave. Now, after 13 years of continuous data, the picture is clearer—and stranger.

The bathtub curve isn’t just leaking, and the shape of reliability might look more like an ankle-high wall at the entrance to a walk-in shower. The neat story of early failures, calm middle age, and gentle decline no longer fits the world our drives inhabit. Drives are getting better—or, more precisely, the Drive Stats dataset says that our drives are performing better in data center environments.

So, let’s talk about what our current “bathtub curve” looks like, and how it compares to earlier generations of the analysis.

The TL;DR: Hard drives are getting better, and lasting longer.