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Seagate · Data-centre drive · ST20000NM002H

Seagate Exos X24 20TB

An enterprise drive. Don't let that put you off, as it's the same 3.5in SATA as a NAS drive and fits the same bays.

Capacity
20 TB
Recording
CMR
Speed
7,200 rpm
Warranty
5 years
Workload
550 TB/yr
Failure rate
No failure data

Good for

  • Busy arrays (550 TB a year)
  • Big media libraries
  • RAID, SHR and ZFS rebuilds
  • 5 years' warranty

Not for

  • A desk or bedroom (7,200 rpm is the louder class)

Updated 27 Oct 2026 · Method 2.0

Who the Exos X24 20 TB is for

Pick it for raw capacity in a box that lives out of earshot, because 7,200 rpm enterprise drives are built to run flat out all day, every day. You also get five years' warranty, two more than the cheapest NAS lines. It's CMR, which is what you want anywhere near a RAID or ZFS rebuild.

Watch out for

At 7,200 rpm it's from the louder, warmer class. Fine in a cupboard, less fun on a desk.

Backblaze doesn't run enough of these for a failure rate we'd publish. Seagate's datasheet puts it at 28 dB idle and 32 dB seeking. Power draw is 6.3 W idle on Seagate's figures, or 55 kWh a year if it spends the whole year idling. Put four in RAID 5 and you'll have 60 TB to fill (Windows will call it 54.6 TB).