Cloud backup provider Backblaze has released its hard drive reliability statistics for the second quarter of 2020.
The company compared active hard drives used in its operations from Seagate, Toshiba, and HGST to compile the report.
Reliability was measured as an annualised failure rate, calculated using the number of drive failures relative to the number of active drive days for each disk.
Backblaze recorded the number of failures for each hard drive from 1 April to 30 June 2020, extrapolating the annualised failure rate from this data.
The company tested a total of 139,867,764 hard drives this quarter, equating to a total of 12,255,625 days worth of hard drive operation across all products.
During this testing period, Backblaze recorded the lowest annualise failure of any quarter it had measured since it first began keeping track in 2013 – 0.81%.
“We deployed 12,063 new drives and removed 1,960 drives via replacements and migration in Q2, giving us a net of 10,103 added drives,” Backblaze said.
“During this quarter, three drive models had zero drive failures: the Toshiba 4TB, the Seagate 6TB, and the HGST 8TB.”
Backblaze excluded drive models for which it did not have at least 60 models from the comparison.
Q2 2020 Failure Rates
The most reliable hard drives for Q2 2020 are listed below, along with their annualised failure rates calculated from their performance during the quarter.
| Model | Drives | Drive Days | Failures | Failure Rate |
|---|---|---|---|---|
| 4TB Hard Drives | ||||
| Toshiba MD04ABA400V | 99 | 9,009 | 0 | 0.00% |
| HGST HMS5C4040BLE640 | 12,739 | 1,159,472 | 9 | 0.28% |
| HGST HMS5C4040ALE640 | 2,952 | 266,200 | 1 | 0.14% |
| Seagate ST4000DM000 | 19,093 | 1,739,577 | 49 | 1.03% |
| 6TB Hard Drives | ||||
| Seagate ST6000DX000 | 886 | 80,626 | 0 | 0.00% |
| 8TB Hard Drives | ||||
| HGST HUH728080ALE600 | 1,000 | 91,000 | 0 | 0.00% |
| Seagate ST8000DM002 | 9,795 | 890,937 | 17 | 0.70% |
| Seagate ST8000NM0055 | 14,462 | 1,316,313 | 33 | 0.92% |
| 10TB Hard Drives | ||||
| Seagate ST10000NM0086 | 1,200 | 109,200 | 2 | 0.67% |
| 12TB Hard Drives | ||||
| HGST HUH721212ALE600 | 2,600 | 200,188 | 3 | 0.55% |
| HGST HUH721212ALN604 | 10,846 | 986,674 | 19 | 0.70% |
| Seagate ST12000NM0007 | 35,095 | 3,319,854 | 82 | 0.90% |
| Seagate ST12000NM0008 | 15,543 | 1,279,568 | 27 | 0.77% |
| 14TB Hard Drives | ||||
| Toshiba MG07ACA14TA | 8,699 | 663,647 | 20 | 1.10% |
| 16TB Hard Drives | ||||
| Seagate ST16000NM001G | 59 | 5,431 | 1 | 6.72% |
Lifetime Failure Rates
The table below shows the reliability of hard drive models Backblaze had in service as of 30 June 2020.
The reporting period is from 1 April 2013 through 30 June 2020.
| Model | Drives | Failure Rate | ||
|---|---|---|---|---|
| 4TB Hard Drives | ||||
| HGST HMS5C4040BLE640 | 12,739 | 0.44% | ||
| HGST HMS5C4040ALE640 | 2.952 | 0.51% | ||
| Toshiba MD04ABA400V | 99 | 0.72% | ||
| Seagate ST4000DM000 | 19,093 | 2.58% | ||
| 6TB Hard Drives | ||||
| Seagate ST6000DX000 | 886 | 1.01% | ||
| 8TB Hard Drives | ||||
| HGST HUH728080ALE600 | 1,000 | 0.64% | ||
| Seagate ST8000DM002 | 9,795 | 1.04% | ||
| Seagate ST8000NM0055 | 14,462 | 1.20% | ||
| 10TB Hard Drives | ||||
| Seagate ST10000NM0086 | 1,200 | 0.74% | ||
| 12TB Hard Drives | ||||
| HGST HUH721212ALE600 | 2,600 | 0.44% | ||
| HGST HUH721212ALN604 | 10,846 | 0.48% | ||
| Seagate ST12000NM0008 | 15,543 | 1.02% | ||
| Seagate ST12000NM0007 | 35,095 | 2.22% | ||
| 14TB Hard Drives | ||||
| Toshiba MG07ACA14TA | 8,699 | 1.06% | ||
| 16TB Hard Drives | ||||
| Seagate ST16000NM001G | 59 | 3.49% | ||