Western Digital Ultrastar DC HC520 12TB 7200RPM SAS 12Gb/s 3.5-inch Helium Enterprise HDD

The Western Digital Ultrastar DC HC520 (HUH721212AL5204) is a 12TB, 7200RPM enterprise-class hard disk drive built on Western Digital's HelioSeal helium-sealed platform. The hermetically sealed design fills the enclosure with helium rather than air, reducing internal drag and turbulence to enable higher areal density, lower operating power, and a reduced thermal footprint compared to conventional air-filled drives. The SAS 12Gb/s interface delivers the dual-port reliability and high-throughput connectivity demanded by enterprise storage systems, while the 3.5-inch form factor ensures broad compatibility with standard datacenter server and JBOD enclosures.

Engineered for continuous 24×7 operation, the HC520 carries a 550TB per year workload rating, making it well-suited to the sustained, high-duty-cycle environments found in large-scale storage arrays, cloud infrastructure, and archive tiers. The drive incorporates Western Digital's MTBF rating of 2,500,000 hours, reflecting the component-level reliability standards expected in mission-critical deployments. Features such as Rotational Vibration Safeguard (RVS) actively compensate for the multi-drive vibration present in dense chassis configurations, preserving read/write accuracy in high-density rack environments.

The AL5204 designation within the HUH721212AL5204 part number identifies the SAS 12Gb/s interface variant with 512e sector size, distinguishing it from companion 4Kn and SATA configurations in the same product family. With a 256MB cache buffer, the drive sustains throughput across sequential workloads typical of surveillance, backup repositories, big data analytics, and AI training data lakes. The combination of helium-sealed mechanics, enterprise-grade error recovery, and dual-port SAS connectivity positions the Ultrastar DC HC520 as a dependable capacity-tier component for organizations building scalable, high-availability storage infrastructure across datacenter, cloud, and edge deployments.

Ideal for

• Hyperscale and cloud object storage nodes requiring high-capacity, high-duty-cycle drives operating continuously at full workload ratings
• Enterprise NAS and SAN arrays where dual-port SAS 12Gb/s connectivity provides redundant path access and hot-swap serviceability
• AI and machine learning training data repositories that demand dense, cost-efficient bulk storage for large unstructured datasets
• Backup and disaster recovery appliances that sustain high sequential write throughput across extended backup windows
• Video surveillance archival storage platforms requiring reliable 24×7 write endurance at high sustained data rates
• Big data analytics clusters where high-capacity helium drives reduce rack space and power consumption per petabyte of usable storage

Technical specifications

Available from Omnixon Global. Submit an RFQ and our team will confirm configuration and availability for your order.