Seagate 16TB Exos X18 7200 rpm SAS III 12 Gb/s 3.5″ Internal HDD – ST16000NM004J

The Seagate 16TB Exos X18 7200 rpm SAS III 12 Gb/s 3.5″ Internal HDD (ST16000NM004J) is an enterprise-grade hard disk drive designed for demanding data center, cloud, and hyperscale applications.¹ This drive emphasizes high capacity, performance, and robust reliability for 24/7 operation.²

Key Features & Specifications

The ST16000NM004J is built to handle intensive workloads, making it distinct from consumer-grade drives:³

• Capacity: A massive 16TB of storage, providing ample space for large datasets and extensive archives.
• Form Factor: Standard 3.5-inch internal hard drive, compatible with most server and storage array enclosures.⁵
• Interface: SAS (Serial Attached SCSI) III 12 Gb/s.⁶ This is a key differentiator from common SATA drives, offering higher throughput, better scalability, and enhanced reliability features.⁷
• Rotational Speed (RPM): 7200 RPM, providing good performance for a mechanical hard drive.⁸
• Cache: 256MB multi-segmented cache, which helps improve data transfer efficiency and overall responsiveness.⁹
• Max. Sustained Transfer Rate (OD): Up to 270 MB/s, indicating strong sequential read/write performance.¹⁰
• Reliability:
  • Mean Time Between Failures (MTBF): 2.5 million hours, a testament to its enterprise-grade durability.¹¹
  • Workload Rating: Designed for a high workload rating of 550 TB per year, suitable for continuous operation in data centers.
  • 5-year limited warranty, providing long-term assurance.¹²
• Power Management: Features like PowerChoice™ Idle Power Technology and PowerBalance™ optimize power consumption, helping to reduce the total cost of ownership (TCO) in large deployments.¹³
• Data Protection & Security: May include Seagate Secure™ features (depending on the specific sub-model), offering hardware-based encryption for enhanced data security.
• Digital Environmental Sensors: Monitor internal drive conditions for optimal operation and performance.¹⁴

SAS vs. SATA: What’s the Difference for this HDD?

• Speed and Throughput: SAS III (12 Gb/s) offers double the theoretical bandwidth of SATA III (6 Gb/s).
• Reliability and Error Handling: SAS typically has more advanced error detection and correction capabilities and is built for 24/7 continuous operation with higher MTBF ratings.¹⁶ The ST16000NM004J, for instance, has a non-recoverable read error rate of 1 sector per ¹⁷1015 bits read, which is an extremely low error rate crucial for critical data.¹⁸
• Scalability: SAS supports multiple devices per port and allows for dual-port functionality, enabling redundant paths to the drive.¹⁹ This is vital for high-availability systems where uninterrupted access is critical. SATA is generally single-port.
• Command Queuing: SAS supports much deeper command queues (up to 254 commands) compared to SATA’s Native Command Queuing (NCQ) (typically 32 commands). This allows SAS controllers to manage multiple simultaneous I/O requests more efficiently, leading to better performance in demanding, multi-user environments.
• Cost: SAS drives and controllers are generally more expensive than their SATA counterparts due to their advanced features and enterprise focus.²⁰
• Compatibility: SAS controllers are backward compatible with SATA drives, meaning you can connect a SATA drive to a SAS port.