{
  "slug": "backblaze-2025-boot-ssd-afr",
  "title": "Backblaze SSD models in 2025: drive days, failures and the AFR upper bound",
  "kind": "dataset",
  "summary": "Exposure and failures for the SSD models in Backblaze's raw Drive Stats files for 2025 (January 1 to December 31, 2025). Sample: 20 SSD models, 1,075,258 drive days, 2,972 drives on December 31, and zero failures. With no failures the file gives each model's exact 95% upper bound on the annualized failure rate: 0.13% for all SSD models pooled, and 0.34% to 4.30% for the models with 10,000 or more drive days. One fleet, mostly boot drives, so it does not describe SSDs in general.",
  "license": "Derivative table computed from the Backblaze Drive Stats daily files for 2025. Cite Backblaze if you use it. You are solely responsible for how you use it. Backblaze's dataset page allows sale of derivative works and forbids selling the Drive Stats data itself. This CSV is a 21-row aggregate, not the daily SMART archive, and that archive is not for sale.",
  "licenseUrl": "https://www.backblaze.com/cloud-storage/resources/hard-drive-test-data",
  "sourceUrl": "https://www.backblaze.com/cloud-storage/resources/hard-drive-test-data",
  "accessed": "2026-10-10",
  "rowCount": 21,
  "columns": [
    {
      "name": "model",
      "type": "string",
      "description": "Model string exactly as in the Backblaze daily files. SSD models were picked by name patterns listed in the step 1 script. The Dell BOSS virtual disk is not included."
    },
    {
      "name": "capacity_gb",
      "type": "integer",
      "description": "Nominal capacity in gigabytes (capacity_bytes / 1e9, rounded). Empty on the pooled row."
    },
    {
      "name": "drive_days_q1",
      "type": "integer",
      "description": "Daily rows of the model from 2025-01-01 to 2025-03-31."
    },
    {
      "name": "drive_days_q2",
      "type": "integer",
      "description": "Daily rows from 2025-04-01 to 2025-06-30."
    },
    {
      "name": "drive_days_q3",
      "type": "integer",
      "description": "Daily rows from 2025-07-01 to 2025-09-30."
    },
    {
      "name": "drive_days_q4",
      "type": "integer",
      "description": "Daily rows from 2025-10-01 to 2025-12-31."
    },
    {
      "name": "drive_days",
      "type": "integer",
      "description": "Sum of the four quarters. This is the exposure."
    },
    {
      "name": "drives_2025_12_31",
      "type": "integer",
      "description": "Drives in the 2025-12-31 file that have a power-on-hours value."
    },
    {
      "name": "median_age_years_2025_12_31",
      "type": "number",
      "description": "Median smart_9_raw of those drives divided by 8766, two decimals. Power-on hours as reported."
    },
    {
      "name": "failures",
      "type": "integer",
      "description": "Rows with failure = 1 in 2025. Zero for every model."
    },
    {
      "name": "afr_percent",
      "type": "number",
      "description": "failures / drive_days * 365 * 100, two decimals. Computed here."
    },
    {
      "name": "afr_high95",
      "type": "number",
      "description": "Upper end of the exact two-sided 95% Poisson interval for zero failures, -ln(0.025) / (drive_days / 365) * 100, two decimals. The lower end is 0."
    }
  ],
  "downloadPath": "/data/datasets/backblaze-2025-boot-ssd-afr.csv",
  "chartPath": "/data/datasets/backblaze-2025-boot-ssd-afr.svg",
  "citations": [
    {
      "id": "bb-data-Q1",
      "title": "Backblaze Hard Drive Test Data, data_Q1_2025.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q1_2025.zip",
      "accessed": "2026-10-10"
    },
    {
      "id": "bb-data-Q2",
      "title": "Backblaze Hard Drive Test Data, data_Q2_2025.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q2_2025.zip",
      "accessed": "2026-10-10"
    },
    {
      "id": "bb-data-Q3",
      "title": "Backblaze Hard Drive Test Data, data_Q3_2025.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q3_2025.zip",
      "accessed": "2026-10-10"
    },
    {
      "id": "bb-data-Q4",
      "title": "Backblaze Hard Drive Test Data, data_Q4_2025.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q4_2025.zip",
      "accessed": "2026-10-10"
    },
    {
      "id": "bb-terms",
      "title": "Backblaze Hard Drive Test Data page and use terms",
      "url": "https://www.backblaze.com/cloud-storage/resources/hard-drive-test-data",
      "accessed": "2026-10-10"
    }
  ]
}