{
  "slug": "nand-erase-block-size-gc-cost",
  "title": "NAND erase blocks grew from 64 pages to as many as 576, and in one simulation write amplification rose from 2.1 to 5.1 with block size",
  "kind": "dataset",
  "summary": "NAND is erased in whole blocks: 256 KB (64 pages) with a 1.5 ms erase in a 2008 part (Agrawal et al.), 128 to 192 pages per block in 2D and up to 576 in 3D NAND (Liu et al.), where simulated write amplification rose from 2.1 to 5.1 with block size. Each extra bit per cell cuts program/erase lifetime 10 to 20 times (Grupp et al.).",
  "license": "Small derived table of figures printed in Agrawal et al. (ATC 2008), Liu et al. (FAST 2018), Grupp et al. (FAST 2012), and Cai et al. (Proceedings of the IEEE 2017), with credit. Not a Creative Commons license. The papers remain with their authors or publishers. This file is not a copy of the papers and not the data.",
  "licenseUrl": "https://www.usenix.org/system/files/conference/fast18/fast18-liu.pdf",
  "sourceUrl": "https://www.usenix.org/system/files/conference/fast18/fast18-liu.pdf",
  "accessed": "2026-10-11",
  "rowCount": 16,
  "columns": [
    {
      "name": "measure",
      "type": "string",
      "description": "The quantity as the source names it."
    },
    {
      "name": "value_low",
      "type": "number",
      "description": "Lower end of a printed range. Empty when the source prints a single value."
    },
    {
      "name": "value_high",
      "type": "number",
      "description": "Single printed value, or the upper end of a range. For 'over' or 'up to' it is the stated bound."
    },
    {
      "name": "unit",
      "type": "string",
      "description": "Unit of the value columns: KB, microseconds, milliseconds, cycles, pages, ratio, percent, or times."
    },
    {
      "name": "scope",
      "type": "string",
      "description": "Population and window the value applies to."
    },
    {
      "name": "note",
      "type": "string",
      "description": "What the value is not, or the source wording behind it."
    },
    {
      "name": "citation_id",
      "type": "string",
      "description": "Id of the opened source in the citations list."
    }
  ],
  "downloadPath": "/data/datasets/nand-erase-block-size-gc-cost.csv",
  "humanPage": "https://hesela.com/analyses/nand-erase-block-size-gc-cost/",
  "limits": [
    "The sources use different parts and years; the 2008 times and endurance are not current figures.",
    "The write amplification result is a simulation with a block-level FTL; page-level FTLs do not show it.",
    "Partial erase is a proposal that needs chip support.",
    "Pages-per-block ranges vary by vendor and generation.",
    "The sources give no 3D NAND erase times beyond saying they are longer."
  ],
  "citations": [
    {
      "id": "agrawal-atc08-pdf",
      "title": "Design Tradeoffs for SSD Performance, Agrawal, Prabhakaran, Wobber, Davis, Manasse, and Panigrahy, USENIX ATC 2008 (USENIX PDF, section 2 and table 1)",
      "url": "https://www.usenix.org/legacy/event/usenix08/tech/full_papers/agrawal/agrawal.pdf",
      "accessed": "2026-10-11"
    },
    {
      "id": "liu-fast18-pdf",
      "title": "PEN: Design and Evaluation of Partial-Erase for 3D NAND-Based High Density SSDs, Liu, Kotra, et al., USENIX FAST 2018 (USENIX PDF, sections 2 and 6)",
      "url": "https://www.usenix.org/system/files/conference/fast18/fast18-liu.pdf",
      "accessed": "2026-10-11"
    },
    {
      "id": "grupp-fast12-pdf",
      "title": "The Bleak Future of NAND Flash Memory, Grupp, Davis, and Swanson, USENIX FAST 2012 (USENIX PDF, introduction)",
      "url": "https://www.usenix.org/legacy/event/fast12/tech/full_papers/Grupp.pdf",
      "accessed": "2026-10-11"
    },
    {
      "id": "cai-procieee17-pdf",
      "title": "Error Characterization, Mitigation, and Recovery in Flash-Memory-Based Solid-State Drives, Cai, Ghose, Haratsch, Luo, and Mutlu, Proceedings of the IEEE, September 2017 (arXiv 1706.08642, section 2)",
      "url": "https://arxiv.org/pdf/1706.08642",
      "accessed": "2026-10-11"
    }
  ]
}