WUH721818AL5201 Western Digital Ultrastar DC HC550 18TB 7.2K RPM SAS-12Gbps HDD

The Western Digital WUH721818AL5201 18TB 7.2K RPM HDD

The Western Digital WUH721818AL5201 Ultrastar DC HC550 18TB hard disk drive is designed to deliver next‑generation storage capacity and performance in demanding data center environments. This high‑capacity SAS HDD offers a balanced combination of storage density, reliability, power efficiency, and performance for workloads that require massive storage scalability without sacrificing operational uptime. Built on a helium platform with 7,200 RPM rotational speed and a 12Gbps SAS interface, the Ultrastar DC HC550 series represents an ideal choice for enterprise servers, high‑availability storage systems, NAS arrays, and cloud‑based infrastructures that demand dependable, high‑capacity storage solutions.

Massive 18TB Storage Capacity

The standout feature of the Western Digital Ultrastar DC HC550 is its enormous 18TB capacity, enabling organizations to store and manage extensive volumes of data on fewer drives. A single 18TB HDD dramatically reduces physical drive count in server racks, lowering maintenance complexity and optimizing server bay utilization. This scale of storage is especially valuable for businesses engaged in big data analytics, digital archiving, virtualized environments, and media‑rich workloads.

7,200 RPM Performance

The 7,200 RPM spindle speed offers a compelling balance between performance and power efficiency. The helium‑sealed design is a critical engineering choice that reduces internal turbulence, friction, and heat generation compared to traditional air‑filled drives. This results in lower power consumption and cooler operating temperatures, making it well‑suited for high‑density storage arrays that require sustained dependability.

SAS 12Gbps Interface

Featuring a 12Gbps Serial Attached SCSI (SAS) interface, the WUH721818AL5201 ensures high‑throughput connectivity with enterprise servers and storage controllers. SAS is the industry standard for mission‑critical applications due to its superior error handling, dual port capabilities for redundancy, and robust performance under multi‑user, high‑load conditions. With dual ports, administrators can implement failover and load balancing for elevated system uptime.

512MB Cache Buffer & 512e Sector Format

High cache buffer capacity is essential for smoothing data transfer spikes and enhancing random read/write operations. The 512MB cache on this drive helps improve overall responsiveness under heavy transactional workloads. Additionally, the 512e (512 byte emulation) sector format ensures compatibility with legacy systems and file systems while enabling larger physical sector efficiencies that benefit certain types of data workloads.

Reliability and Durability

Ultrastar drives are engineered for enterprise reliability, and the DC HC550 series is no exception. Designed with a workload rating capable of supporting multiple petabytes written per year, these drives are ideal for environments where continuous read/write operations are the norm. Built‑in vibration tolerance, advanced error recovery algorithms, and robust MTBF ratings reduce the risk of drive failure and contribute to higher system availability.

High‑Density Storage Arrays

Storage arrays populated with Ultrastar DC HC550 drives allow for massive capacity with a reduced physical footprint. By offering 18TB in a standard 3.5‑inch form factor, data center architects can design dense storage enclosures with fewer drives, reducing complexity and cooling requirements. This advantage is crucial in enterprise NAS and SAN solutions where rack space is at a premium.

Media & Entertainment Storage Solutions

The media and entertainment industry often handles massive files such as high‑resolution video, audio libraries, and CGI assets. The Ultrastar DC HC550 provides the combined capacity and sustained data throughput needed to archive and serve large media assets with confidence. Video editing suites, broadcast storage servers, and rendering farms all benefit from the high performance and reliability of this HDD series.

Backup, Archival & Compliance Storage

Organizations subject to regulatory compliance or data retention policies need resilient and long‑term storage solutions. Utilizing 18TB drives reduces the number of devices required for backup and archival environments. Backup windows can be optimized, and data retrieval processes benefit from the high throughput and reliability designed into enterprise HDDs like the Ultrastar DC HC550.

Sequential and Random Performance

While HDDs are generally not as fast as SSDs for random access, the Ultrastar DC HC550’s design optimizes performance within the context of spinning disk technology. Sequential read/write speeds are strong for large block data movement, making the drive suitable for streaming workloads and large file transfers. For random performance, the large cache buffer helps smooth out access latencies and contributes to consistent performance under mixed workloads.

Power Efficiency and Thermal Management

Helium‑sealed drives typically consume less power than traditional air‑filled HDDs due to reduced friction and improved aerodynamics of the internal platters. The Western Digital Ultrastar DC HC550 series benefits from this technology, translating into lower energy costs and reduced heat output. Datacenter operators can leverage this efficiency to lower cooling demands, contributing to overall operational cost savings.

Compatibility and Integration 

Server and Storage Controller Compatibility

The Western Digital WUH721818AL5201 Ultrastar DC HC550 is designed to work seamlessly with a wide range of enterprise server platforms and storage controllers that support SAS 12Gbps. Dual port SAS enables multi‑path connectivity, making these drives suitable for redundant storage configurations and high‑availability clusters. IT administrators should verify controller firmware compatibility and ensure proper SAS cabling to fully exploit the drive’s capabilities.

Form Factor 

Featuring the standard 3.5‑inch form factor, the Ultrastar DC HC550 drives are compatible with most server chassis, storage arrays, and expansion enclosures. This ensures straightforward replacement or expansion planning when upgrading existing storage infrastructure. Compatible backplanes and hot‑swap bays allow for drive swaps with minimal downtime.

Reliability and Durability

Advanced Error Correction and Data Integrity

Built with enterprise‑grade error correction and data integrity features, the Ultrastar DC HC550 series helps ensure that your data remains accurate and accessible. These drives include technologies designed to detect and correct media errors, safeguarding stored information even in the event of marginal read conditions. This capability is essential for mission‑critical applications where silent data corruption cannot be tolerated.

18TB vs. Other Capacity Options

The Ultrastar DC HC550 series includes multiple capacity options, ranging from lower‑capacity variants to the high‑density 18TB model. Choosing the 18TB version maximizes storage per bay and minimizes drive count, an advantage in environments where space, power, and cooling are significant cost factors. Lower capacity options may be more cost‑effective per drive initially but lead to higher total drive count for the same aggregate capacity.

Optimizing Storage Architectures with Ultrastar DC HC550

Scaling Storage in SAN and NAS Systems

SAN and NAS administrators can leverage the 18TB Ultrastar drives to scale storage pools efficiently. With fewer drives needed to achieve high capacity, SAN fabric complexity and management overhead decrease. NAS solutions gain similar benefits, with large shared storage volumes available for enterprise file shares, virtualization data stores, and departmental data repositories.

Tiered Storage Strategies

Tiered storage strategies combine different storage media types to balance performance and cost. The Ultrastar DC HC550 can be part of a tier dedicated to high‑capacity, lower‑cost spinning disk storage, while SSD tiers serve high I/O transactional workloads. This approach ensures that frequently accessed data receives the performance it needs, while infrequently accessed data resides on economic, high‑capacity HDDs without compromising on reliability.

Reliable Performance

Designed for 24/7 operation, the Ultrastar DC HC550 series delivers dependable performance across the most demanding workloads. Enterprise‑grade reliability means fewer drive replacements, less data migration, and more confidence that critical data is stored securely and accessible when needed.

Future‑Proof Scalability

As data continues to grow exponentially across every industry, having a storage platform that can scale with that growth is essential. The 18TB Ultrastar DC HC550 drive equips IT architects with the tools necessary to build scalable, resilient storage infrastructures that can adapt to evolving business needs.