Do Bigger Hard Drives Fail Faster? Backblaze Data Reveals What Really Affects HDD Reliabilit

A common belief among PC and NAS users is that larger hard drives are more likely to fail. But Backblaze’s latest drive data shows that storage capacity alone is not a good way to predict HDD reliability. In many cases, the age and model of a drive matter more than whether it has 8TB, 16TB or 24TB of storage.

Backblaze’s Q1 2026 Drive Stats report covers more than 341,000 hard drives. Drives with capacities of 20TB or more recorded an annualized failure rate (AFR) of 0.85%, compared with 1.24% across the company’s entire drive fleet. Some high-capacity models performed particularly well. Toshiba’s 24TB drive had an AFR of 0.22%, while Western Digital’s 22TB model recorded 0.38%. This does not mean every 20TB or 24TB HDD will be more reliable, but it shows that higher capacity does not automatically mean higher failure risk.

One important point is that Backblaze’s larger drives are generally newer. The company buys different capacities based on its storage needs and pricing, so older 4TB and 8TB drives have often been running for much longer. Hard drives can experience different failure rates during their lifetime. Some fail early because of manufacturing or initial-use problems, while others remain reliable for years before failures become more common as components age. This is why comparing HDD capacity without considering drive age and model can give a misleading picture of reliability.

For home NAS storage, there is another important issue: rebuilding a failed drive. When a drive fails in a RAID or other redundant setup, the remaining drives may need to read large amounts of data to rebuild the replacement. A larger HDD can mean more data needs to be processed, potentially making the rebuild period longer. During this time, the storage system can be under additional workload, and another drive failure could create a serious data-loss risk. This is why NAS users should not choose drives based only on capacity. A better approach is to consider drive age, model reliability, workload, RAID or ZFS redundancy, drive health monitoring and separate backups.

The main lesson from Backblaze’s data is simple: a bigger HDD is not automatically a less reliable HDD. When choosing storage, looking at the drive’s age, model, workload and backup strategy provides a much better understanding of the real risks.

Information referenced in this article is from XDA Developers