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HGST HMS5C4040ALE640 4 TB failure rate and reliability
A Grade A: Excellent
Backblaze logged 4,207 drive-years on the HGST HMS5C4040ALE640 from Q1 2023 to Q3 2026. In that time 16 drives failed, an annualised failure rate of 0.38%.
That is 75% lower than the 1.52% average across every drive in the same data, which earns it grade A (excellent).
Among the 3 graded 4 TB hard drives it ranks 2 of 3 for reliability.
The rate has been steady: 0.33% over the latest 7 quarters against 0.38% before.
Backblaze no longer runs this model, so these figures are historical.
- Failure rate / year
- 0.38%
- Average, all drives
- 1.52%
- Drives in use
- 0
- Drive-years
- 4,207
- Failures
- 16
- Capacity
- 4 TB
- Type
- HDD
- Model number
- HMS5C4040ALE640
Failure rate by quarter
| Quarter | Drive-days | Failures | Failure rate / year |
|---|---|---|---|
| Q1 2023 | 334,847 | 1 | 0.11% |
| Q2 2023 | 326,504 | 4 | 0.45% |
| Q3 2023 | 308,368 | 2 | 0.24% |
| Q4 2023 | 212,426 | 5 | 0.86% |
| Q1 2024 | 160,387 | 2 | 0.46% |
| Q2 2024 | 83,549 | 1 | 0.44% |
| Q3 2024 | 57,682 | 1 | 0.63% |
| Q4 2024 | 25,496 | 0 | 0.00% |
| Q1 2025 | 22,302 | 0 | 0.00% |
| Q2 2025 | 990 | 0 | 0.00% |
| Q3 2025 | 1,012 | 0 | 0.00% |
| Q4 2025 | 1,012 | 0 | 0.00% |
| Q1 2026 | 944 | 0 | 0.00% |
Single quarters with few drive-days swing widely; the overall figure above is the dependable one.
All 4 TB hard drives compared
| Grade | Model | Type | Size | Failure rate / year | Drives in use | Drive-years | Failures |
|---|---|---|---|---|---|---|---|
| A | HGST HMS5C4040BLE640 | HDD | 4 TB | 0.32% | 0 (retired) | 21,067 | 67 |
| A | HGST HMS5C4040ALE640 | HDD | 4 TB | 0.38% | 0 (retired) | 4,207 | 16 |
| D | Seagate ST4000DM000 | HDD | 4 TB | 3.46% | 0 (retired) | 20,249 | 701 |
| – | Toshiba MD04ABA400V | HDD | 4 TB | 1.04% | 0 (retired) | 96 | 1 |
| – | HGST HUS726040ALE610 | HDD | 4 TB | 0.00% | 0 (retired) | 53 | 0 |
| – | Seagate ST4000DM005 | HDD | 4 TB | 5.27% | 0 (retired) | 38 | 2 |