{
  "slug": "storage-interface-payload-ceilings",
  "title": "Payload ceilings of SATA, SAS and PCIe x4 links by generation",
  "kind": "dataset",
  "summary": "Theoretical one-direction payload ceilings for 14 storage-link generations: SATA 1.0 to 3.0, SAS-1 to SAS-4 (one lane), and PCIe 1.0 to 7.0 at four lanes. Each value is the published line rate times the line-code efficiency, and nothing is measured. SATA 3.0 gives 600 MB/s, SAS-4 gives 2,400 MB/s, PCIe 4.0 x4 gives 7,877 MB/s and PCIe 7.0 x4 gives 60,500 MB/s. Real drives and protocols stay below these ceilings.",
  "license": "The line rates, line codes and release years are public facts about the SATA, SAS and PCIe standards. No specification text is copied and the specifications are not reproduced. The efficiency and ceiling columns are arithmetic done on this site. Reuse is fine with attribution to the standards bodies named in the sources. This is a small derived table and not a dump of any source.",
  "licenseUrl": "https://en.wikipedia.org/wiki/Wikipedia:Copyrights",
  "sourceUrl": "https://en.wikipedia.org/wiki/PCI_Express",
  "accessed": "2026-10-10",
  "rowCount": 14,
  "columns": [
    {
      "name": "interface",
      "type": "string",
      "description": "Interface family: SATA, SAS, or PCIe."
    },
    {
      "name": "generation",
      "type": "string",
      "description": "Specification generation as named by its standards body."
    },
    {
      "name": "spec_year",
      "type": "integer",
      "description": "Year the generation was released or approved, per the cited summaries."
    },
    {
      "name": "line_rate_gtps",
      "type": "number",
      "description": "Signalling rate per lane in gigatransfers per second (equal to Gbit/s on the coded line)."
    },
    {
      "name": "line_code",
      "type": "string",
      "description": "Line code or framing assumed for payload accounting."
    },
    {
      "name": "coding_efficiency_percent",
      "type": "number",
      "description": "Payload bits divided by coded bits, in percent. Computed here."
    },
    {
      "name": "lanes",
      "type": "integer",
      "description": "Lanes in the link the last column refers to: 1 for SATA and SAS, 4 for PCIe (the usual NVMe SSD link)."
    },
    {
      "name": "payload_gbps_per_lane",
      "type": "number",
      "description": "Line rate times coding efficiency, Gbit/s per lane, one direction. Computed here."
    },
    {
      "name": "payload_mb_s_per_lane",
      "type": "integer",
      "description": "Same in MB/s (10^6 bytes), rounded half up."
    },
    {
      "name": "payload_mb_s_link",
      "type": "integer",
      "description": "Per-lane value times lanes, from unrounded values and then rounded half up. One direction, before protocol overhead."
    }
  ],
  "downloadPath": "/data/datasets/storage-interface-payload-ceilings.csv",
  "chartPath": "/data/datasets/storage-interface-payload-ceilings.svg",
  "citations": [
    {
      "id": "pcie-wiki",
      "title": "PCI Express (comparison table of line codes, transfer rates and throughput; summarises PCI-SIG documents)",
      "url": "https://en.wikipedia.org/wiki/PCI_Express",
      "accessed": "2026-10-10"
    },
    {
      "id": "sas-wiki",
      "title": "Serial Attached SCSI (history, 8b/10b and 128b/150b encoding; summarises T10 standards)",
      "url": "https://en.wikipedia.org/wiki/Serial_Attached_SCSI",
      "accessed": "2026-10-10"
    },
    {
      "id": "sata-wiki",
      "title": "Serial ATA (revisions and usable rates; summarises SATA-IO releases)",
      "url": "https://en.wikipedia.org/wiki/Serial_ATA",
      "accessed": "2026-10-10"
    },
    {
      "id": "t10",
      "title": "T10 technical committee, SAS standards",
      "url": "https://www.t10.org/",
      "accessed": "2026-10-10"
    },
    {
      "id": "pcisig",
      "title": "PCI-SIG specifications",
      "url": "https://pcisig.com/specifications",
      "accessed": "2026-10-10"
    },
    {
      "id": "sata-io",
      "title": "SATA-IO",
      "url": "https://sata-io.org/",
      "accessed": "2026-10-10"
    }
  ]
}