page_title: Serial ATA
section_title: eSATA
hierarchical_section_title: Serial ATA / Cables, connectors, and ports / eSATA
caption_attribution_description: Deutsch: Steckverbindung eSATA
context_page_description: Serial ATA is a computer bus interface that connects host bus adapters to mass storage devices such as hard disk drives, optical drives, and solid-state drives. Serial ATA succeeded the earlier Parallel ATA standard to become the predominant interface for storage devices.
  Serial ATA industry compatibility specifications originate from the Serial ATA International Organization which are then promulgated by the INCITS Technical Committee T13, AT Attachment.
context_section_description: Standardized in 2004, eSATA (e standing for external) provides a variant of SATA meant for external connectivity.  It uses a more robust connector, longer shielded cables, and stricter (but backward-compatible) electrical standards.  The protocol and logical signaling (link/transport layers and above) are identical to internal SATA.  The differences are:
  Minimum transmit amplitude increased: Range is 500–600 mV instead of 400–600 mV.
  Minimum receive amplitude decreased: Range is 240–600 mV instead of 325–600 mV.
  Maximum cable length increased to 2 metres (6.6 ft) from 1 metre (3.3 ft).
  The eSATA cable and connector is similar to the SATA 1.0a cable and connector, with these exceptions:
  The eSATA connector is mechanically different to prevent unshielded internal cables from being used externally. The eSATA connector discards the "L"-shaped key and changes the position and size of the guides.
  The eSATA insertion depth is deeper: 6.6 mm instead of 5 mm. The contact positions are also changed.
  The eSATA cable has an extra shield to reduce EMI to FCC and CE requirements. Internal cables do not need the extra shield to satisfy EMI requirements because they are inside a shielded case.
  The eSATA connector uses metal springs for shield contact and mechanical retention.
  The eSATA connector has a design-life of 5,000 matings; the ordinary SATA connector is only specified for 50.
  Aimed at the consumer market, eSATA enters an external storage market served also by the USB and FireWire interfaces. The SATA interface has certain advantages. Most external hard-disk-drive cases with FireWire or USB interfaces use either PATA or SATA drives and "bridges" to translate between the drives' interfaces and the enclosures' external ports; this bridging incurs some inefficiency. Some single disks can transfer 157 MB/s during real use, about four times the maximum transfer rate of USB 2.0 or FireWire 400 (IEEE 1394a) and almost twice as fast as the maximum transfer rate of FireWire 800. The S3200 FireWire 1394b specification reaches around 400 MB/s (3.2 Gbit/s), and USB 3.0 has a nominal speed of 5 Gbit/s. Some low-level drive features, such as S.M.A.R.T., may not operate through some USB or FireWire or USB+FireWire bridges; eSATA does not suffer from these issues provided that the controller manufacturer (and its drivers) presents eSATA drives as ATA devices, rather than as SCSI devices, as has been common with Silicon Image, JMicron, and NVIDIA nForce drivers for Windows Vista. In those cases SATA drives do not have low-level features accessible.
  The eSATA version of SATA 6G operates at 6.0 Gbit/s (the term "SATA III" is avoided by the SATA-IO organization to prevent confusion with SATA II 3.0 Gbit/s, which was colloquially referred to as "SATA 3G" [bit/s] or "SATA 300" [MB/s] since the 1.5 Gbit/s SATA I and 1.5 Gbit/s SATA II were referred to as both "SATA 1.5G" [bit/s] or "SATA 150" [MB/s]). Therefore, eSATA connections operate with negligible differences between them. Once an interface can transfer data as fast as a drive can handle them, increasing the interface speed does not improve data transfer.
  There are some disadvantages, however, to the eSATA interface:
  Devices built before the eSATA interface became popular lack external SATA connectors.
  For small form-factor devices (such as external 2.5-inch (64 mm) disks), a PC-hosted USB or FireWire link can usually supply sufficient power to operate the device. However, eSATA connectors cannot supply power, and require a power supply for the external device. The related eSATAp (but mechanically incompatible, sometimes called eSATA/USB) connector adds power to an external SATA connection, so that an additional power supply is not needed.
  As of mid 2017 few new computers have dedicated external SATA (eSATA) connectors, with USB3 dominating and USB3 Type C, often with the Thunderbolt alternate mode, starting to replace the earlier USB connectors. Still sometimes present are single ports supporting both USB3 and eSATA.
  Desktop computers without a built-in eSATA interface can install an eSATA host 
caption: eSATA ports
exif: {"Image Make": "PENTAX", "Image Model": "PENTAX K-x", "Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "PENTAX Digital Camera Utility Ver. 4.31", "Image DateTime": "2010:11:08 21:50:52", "Image Artist": "Rainer Knaepper", "Image YCbCrPositioning": "Co-sited", "Image Copyright": "Rainer Knaepper", "Image ExifOffset": "306", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "46670", "Thumbnail JPEGInterchangeFormatLength": "3710", "EXIF ExposureTime": "4", "EXIF FNumber": "16", "EXIF ExposureProgram": "Manual", "EXIF ISOSpeedRatings": "200", "EXIF ExifVersion": "0221", "EXIF DateTimeOriginal": "2010:11:08 17:52:13", "EXIF DateTimeDigitized": "2010:11:08 17:52:13", "EXIF ComponentsConfiguration": "YCbCr", "EXIF ExposureBiasValue": "0", "EXIF MeteringMode": "Pattern", "EXIF Flash": "Flash did not fire, compulsory flash mode", "EXIF FocalLength": "55", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "1797", "EXIF ExifImageLength": "1800", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "EXIF InteroperabilityOffset": "46546", "EXIF SensingMethod": "One-chip color area", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Manual Exposure", "EXIF WhiteBalance": "Auto", "EXIF FocalLengthIn35mmFilm": "82", "EXIF SceneCaptureType": "Standard", "EXIF Contrast": "Normal", "EXIF Saturation": "Normal", "EXIF Sharpness": "Soft", "EXIF SubjectDistanceRange": "1"}