Seagate ST500NM0021 500GB SAS Hard Drive

Seagate Part #/MPN: ST500NM0021

DiscTech Item #: SGT-ST500NM0021-BN-5Y

  • Low Stock:Call for ETA
    Stock Levels

    This item is currently (nearly) out of stock. It may be possible to arrange fast shipment. If you need it urgently call us. Otherwise, it usually ships within 1 week.


Enterprise Grade

Capacity: 500GB

Speed: 7,200RPM

Interface Types: SAS Serial Attached SCSI

Form Factor: 3.5inx1.0in LFF Hard Drive

Encryption/SED Supported

Sector Size: 512 / 512e

Sustained Throughput: 62 to 152

Average Seek Time: 8.3/9.3

Electrical Interface: SAS-2 Serial Attached SCSI v2 - 6.0Gbps

On-Board Cache: 64MB

Seagate ST500NM0021 500GB 3.5in 6Gbps 7.2K RPM HS SED Constellation ES.1 SAS HDD - Brand New

Seagate ST500NM0021 500GB 3.5" 6.0 Gbps 7200 RPM Hot Swappable Self-Encrypting Drive Constellation ES.1 Serial Attached SCSI Hard Disk Drive - Brand New

Constellation ES.1 drives provide high performance, high capacity data storage for a variety of systems including engineering workstations, network servers, mainframes, and supercomputers. The Serial Attached SCSI interface is designed to meet next-generation computing demands for performance, scalability, flexibility and high-density storage requirements.

Constellation ES.1 drives are random access storage devices designed to support the Serial Attached SCSI Protocol as described in the ANSI specifications. Constellation ES.1 drives are classified as intelligent peripherals and provide level 2 conformance (highest level) with the ANSI SCSI-1 standard.

The Self-Encrypting Drive models indicated on the cover of this product manual have provisions for “Security of Data at Rest” based on the standards defined by the Trusted Computing Group.

The head and disk assembly (HDA) is sealed at the factory. Air recirculates within the HDA through a non-replaceable filter to maintain a contamination-free HDA environment.

Constellation ES.1 drives use a dedicated load/unload zone at the outermost radius of the media to eliminate the possibility of destroying or degrading data by landing in the data zone. The heads automatically go to the ramp load/unload when power is removed from the drive.

An automatic shipping lock prevents potential damage to the heads and discs that results from movement during shipping and handling. The shipping lock disengages and the head load process begins when power is applied to the drive.

Constellation ES.1 drives decode track 0 location data from the servo data embedded on each surface to eliminate mechanical transducer adjustments and related reliability concerns.

The drives also use a high-performance actuator assembly with a low-inertia, balanced, patented, straight arm design that provides excellent performance with minimal power dissipation.

Constellation ES.1 drives have the following standard features:

  • Perpendicular recording technology
  • 1.5 / 3 / 6 Gb Serial Attached SCSI (SAS) interface
  • Integrated dual port SAS controller supporting the SCSI protocol
  • Support for SAS expanders and fanout adapters
  • Firmware downloadable using the SAS interface
  • 128 - deep task set (queue)
  • Supports up to 32 initiators
  • Jumperless configuration.
  • User-selectable logical block size (512, 520 or 528 bytes per logical block).
  • Industry standard 3.5-inch dimensions
  • Programmable logical block reallocation scheme
  • Flawed logical block reallocation at format time
  • Programmable auto write and read reallocation
  • Reallocation of defects on command (Post Format)
  • ECC maximum burst correction length of 400 bits
  • No preventive maintenance or adjustments required
  • Embedded servo design
  • Dedicated head load/unload zone
  • Self diagnostics performed when power is applied to the drive
  • Vertical, horizontal, or top down mounting
  • 64 Mbyte data buffer
  • Drive Self Test (DST)
  • Background Media Scan (BMS)
  • Idle Read After Write (IRAW)
  • Power Save

Constellation ES.1 SAS Self-Encrypting Drive models have the following additional features:

  • Automatic data encryption/decryption
  • Controlled access
  • Random number generator
  • Drive locking
  • 16 independent data bands
  • Cryptographic erase of user data for a drive that will be repurposed or scrapped
  • Authenticated firmware download


This drive is compatible with any server that accepts 3.5"x1.0" (LFF Hard Drive) SAS Drive.

Drive ModelST500NM0021
InterfaceSAS 6Gb/s
Internal Drive Characteristics
Self-Encrypting Drive (SED)Yes
FIPS 140-2 Level 2No
Read/Write Data Heads2
Bytes Per Track1,012,608
Bytes Per Surface250,000
Tracks Per Surface248,600
Tracks Per Inch237,000
Peak Bits Per Inch1,523,000
Areal Density324
Internal Data Rate95 - 212
Disk Rotation Speed7200
Avg. Rotational Latency4.16
Seek Performance Characteristics
Average Access Time (Typical) Not Including Controller Overhead (Read/Write, ms)8.3/9.3
Average Access Time (Typical) Including Controller Overhead (Read/Write, ms)8.5/9.5
Single Track Access Time (Typical) Not Including Controller Overhead (Read/Write, ms)0.5/0.8
Single Track Access Time (Typical) Including Controller Overhead (Read/Write, ms)0.7/1.0
Full Stroke Access Time (Typical) Not Including Controller Overhead (Read/Write, ms)18/19
Full Stroke Access Time (Typical) Including Controller Overhead (Read/Write, ms)18.2/19.2
Format Command Execution Time for 512-Byte Sector (Minutes) Maximum (With Verify)173
Format Command Execution Time for 512-Byte Sector (Minutes) Maximum (Without Verify)86
General Performance Characteristics
Minimum Sector Interleave1 to 1
Data Buffer To/From Disk Media (One 512-Byte Logical Block)95 to 212 MB/s
Sustained Transfer Rate62 to 152 MB/s
SAS Interface Maximum Instantaneous Transfer Rate600MB/s per port (dual port = 1200MB/s)
Logical Block Sizes512 (Default), 520 or 528
Read/write consecutive sectors on a trackYes
Average Rotational Latency4.16ms
Reliability Specifications
Seek Error RateLess Than 10 Errors in 10E8 Seeks
Read Error Recovered Data RatesLess Than 10 Errors in 10E12 Bits Transferred (OEM Default Setting)
Read Error Unrecovered Data RatesLess Than 1 Sector in 10E15 Bits Transferred
Read Error Miscorrected Data RatesLes Than 1 Sector in 10E21 Bits Transferred
Interface Error RateLess Than 1 Error in 10E12 Bits Transferred
Mean Time Between Failure (MTBF)1,200,000 Hours
Annualized Failure Rate (AFR)0.73%
Preventive MaintenanceNone Required
Hot PlugYes

Click here to view the manufacturer's item description/brochure

ROHS Compliant

Weight: 1.8 lb

Warranty: 5 Year Manufacturer

Brand New

Condition Levels Explained

The product is brand new.

5 Year Manufacturer Warranty

Product Warranties Explained

The product has a manufacturer warranty for the time period specified.