Seagate Exos X20 20TB 3.5" 7200RPM SAS 12Gb/s Enterprise HDD

The Seagate ST20000NM002D is a hard drive that delivers 20 TB of raw storage in a 3.5 inch form factor for servers and storage arrays that run around the clock. It connects through a 12 Gb/s SAS interface and offers dual-port access, making it a natural fit for high-availability backplanes where redundancy and quick failover are required.

Inside the enclosure, the drive spins at 7200 rpm and uses conventional magnetic recording sealed in helium. This sealed design cuts air resistance, which helps the platters move smoothly, keeps temperatures lower, and reduces power draw. A 256 MB cache buffers bursty requests, and a sustained transfer rate up to 285 MB/s maintains steady throughput. Average latency of 4.16 ms keeps random reads and writes responsive even under heavy mixed loads.

Reliability sits at the core of the Exos X20 family. The ST20000NM002D carries a 2.5 million-hour mean time between failures and posts a non-recoverable bit error rate of one in 10¹⁵, so administrators can trust the drive for long-term data retention. It supports both 512e and 4Kn sector formats, so it integrates cleanly with legacy applications as well as modern, high-efficiency file systems. Hot-plug capability, power-choice settings, and Seagate-exclusive firmware tunings give data-center staff the flexibility to balance performance with energy savings.

Typical deployments include dense rack-mount chassis, scalable NAS or SAN appliances, object storage clusters, backup repositories, and surveillance archives. Whether you are spinning up virtual machines, capturing large media files, or building a private cloud that never sleeps, this drive provides the capacity and consistent speed those workloads demand without pushing power budgets beyond reason.

• 20 TB of capacity using conventional magnetic recording inside a helium-sealed enclosure
• 12 Gb/s SAS interface with dual-port architecture for redundant data paths
• Sustained transfer rate up to 285 MB/s backed by a 256 MB cache
• 7200 rpm spindle and 4.16 ms average latency for predictable access times
• 2.5 million-hour MTBF and 1 in 10¹⁵ non-recoverable bit error rate for proven reliability
• Supports both 512e and 4Kn sector formats and allows hot-plug operation
• Typical power usage: 5.8 W at idle, 9.8 W during random reads, 7 W during random writes