DatacenterDisk
Seagate

Seagate Exos X20 20TB SAS

ST20000NM003D
Exos X20CMR20TBSAS-12G3.5"
$43.05/TB
$861.00
REFURBIn Stock
Price updated
Price accurate as of Aug 14, 2026, 10:30 AM
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Quick Verdict

The Seagate Exos X20 20TB SAS is a 20TB SAS-12G enterprise drive at $43.05/TB - CMR recording makes it safe for all RAID levels and NAS deployments. As a refurbished unit, run SMART diagnostics on arrival and verify power-on hours.

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Specifications

Capacity20TB
Form Factor3.5"
InterfaceSAS-12G
Recording TechCMR
RPM7200
Cache—
Sector Size—
Workload Rating—
Warranty5 years
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Market context

Against every other drive we have an in-stock price for today, this one is cheaper per tb than 38% of them (100 of 263). The cheapest we can currently buy is $14.00/TB; the middle of the market is $37.55/TB.

Where the wider market has moved

These are third-party figures about the retail market as a whole, quoted and dated. They are not our own measurements and they do not describe this specific drive.

Compare against every 20TB drive we track →Cheapest per terabyte, all categories →Category price trends →
How it compares - 20TB SAS-12G
#1MDD 20TB SAS 12G 7200RPM Enterprise
$15.50/TB
#2MDD 20TB SAS 12G 7200RPM Enterprise
$15.50/TB
#3Seagate Exos X20 20TB SASTHIS DRIVE
$43.05/TB

Compare to similar 20TB SAS-12G drives

MDD
20TB SAS 12G 7200RPM Enterprise
$15.50/TB
$309.99
new
MDD
20TB SAS 12G 7200RPM Enterprise
$15.50/TB
$309.99
new

Frequently Asked Questions

Yes. The Exos X20 20TB SAS uses CMR recording which is fully compatible with all RAID levels.

5-year manufacturer warranty. This listing is a refurbished/renewed unit - verify seller warranty before purchase.

Compatible with any server or workstation equipped with a SAS HBA or SAS backplane. Tested with Dell PowerEdge, HPE ProLiant, Supermicro and IBM System x platforms.

Use Case Scenarios

🏠
Home & SMB NAS
Building a high-capacity NAS for media, backups and file sharing.
✓ Excellent fit
CMR recording is RAID-safe and fully compatible with Synology, QNAP, TrueNAS and UnRAID. Refurb units offer strong value for non-critical NAS.
💾
Backup Server / Veeam Target
Dedicated backup storage for Veeam, Commvault, or NetBackup.
✓ Excellent fit
20TB SAS drives are ideal for backup targets. Dual-port SAS suits dual-path backup infrastructure.
☁️
Object Storage / Cold Data Tier
High-density storage for MinIO, Ceph or Hadoop at scale.
✓ Excellent fit
At 20TB per drive, a 60-bay JBOD delivers 1200TB raw — enough for petabyte-scale object storage.

Maintenance & Troubleshooting

Maintenance Checklist

On installCheck SMART baseline on arrival
Run smartctl -a /dev/sdX and record: Reallocated_Sector_Ct, Power_On_Hours, Spin_Retry_Count. Critical for refurb drives — refuse any with reallocated sectors > 0.
MonthlyRun SMART short self-test
smartctl -t short /dev/sdX — takes 1-2 minutes, catches most developing issues. Schedule during off-peak.
QuarterlyRun SMART long self-test
smartctl -t long /dev/sdX — full surface scan, takes 10 hours for 20TB. Any test failure is grounds for immediate replacement.
QuarterlyCheck RAID array health
Verify no degraded drives. A degraded array with no hot spare is one failure from data loss. Check mdstat or controller UI.
AnnuallyVerify drive firmware version
Check Seagate support site for firmware updates. Some versions have known bugs affecting integrity.
Every 3-5 yearsPlan proactive replacement
Enterprise HDDs have higher failure rates after year 4-5. At 20TB per drive, budget for replacements before failures occur.

Troubleshooting Guide

Cause: HBA not initialized, SAS expander issue, cable fault, or incompatible controller.
Fix: Verify HBA firmware. Check SAS topology with sas2ircu or StorCLI. Test with known-good cable. Confirm drive is SAS not SATA.