UCS-HD1T7KL12G Cisco 1TB 7.2K RPM SAS-12GBPS LFF HDD

The UCS-HD1T7KL12G is a purpose-built enterprise-class hard disk drive engineered for Cisco UCS platforms and other server and storage arrays that require a 1TB capacity, 7,200 RPM spindle speed, and a high-throughput SAS 12Gbps interface in a large form factor (LFF). This category groups drives and accessories that match the same functional and physical profile — regulated performance characteristics, hot-swap tray compatibility, and the mechanical reliability expected in datacenter and virtualization environments. The description that follows expands technical specifications, compatibility notes, deployment scenarios, performance expectations, lifecycle and maintenance guidelines, procurement considerations, and frequently asked questions for customers, resellers, and systems engineers seeking to select the right UCS-compatible LFF SAS drive for their environment.

Core technical profile

Capacity and form factor

The drive in this category offers 1TB of formatted capacity in a 3.5-inch large form factor (LFF) enclosure. LFF drives are commonly used where higher per-disk capacity and lower cost per GB is prioritized over the higher density of small form factor (SFF) drives. The UCS-HD1T7KL12G typically uses enterprise-grade media and internal formatting optimized for server workloads, providing consistent usable capacity for datacenter operating systems and hypervisors.

Interface and throughput

The defining connectivity feature is the SAS (Serial Attached SCSI) 12Gbps interface. SAS-12Gbps supports full-duplex, high-bandwidth connections between drive and HBA/RAID controller, enabling sustained I/O and low latency for mixed read/write workloads. This interface also allows for backward compatibility to 6Gbps SAS and SATA controllers in many cases (subject to controller policies), but to achieve the rated performance, use with a native 12Gbps SAS host bus adapter or Cisco UCS controller is recommended.

Rotational speed and cache

Rotating at 7,200 RPM, these drives strike a balance between energy consumption and latency. Compared with high-RPM 10K/15K spindle drives, 7.2K offers lower power and cost while delivering acceptable seek times for general purpose workloads. Typical models include multi-megabyte onboard cache (for example, 64MB or higher), which smooths bursty writes and improves effective throughput under mixed access patterns. Check the product datasheet for exact cache size and firmware features.

Compatibility

The UCS-HD1T7KL12G is designed primarily for Cisco Unified Computing System (UCS) chassis and rack servers that accept LFF SAS drives. Supported platforms may include Cisco UCS C-Series and E-Series servers and certain UCS modular chassis; compatibility varies by model and firmware level. Always verify exact part number compatibility with Cisco's hardware compatibility list or your reseller before purchase. In many cases, Cisco servers will check a drive's vendor firmware ID — using Cisco-qualified or Cisco-branded drives avoids unexpected controller warnings or asset tracking mismatches.

Controller and RAID considerations

Use with enterprise SAS HBAs or RAID controllers that support SAS-12Gbps is recommended for full performance. Controllers that support advanced features such as TLER/Time Limited Error Recovery, background patrol reads, and firmware-reporting options will help maintain drive reliability in RAID groups. When mixing drives of different rotational speeds or capacities in the same RAID set, expect performance and rebuild times to be governed by the slowest member; avoid mixing LFF and SFF drives in the same logical array.

Deployment

Tiered storage strategies

In modern datacenters, using multiple storage tiers is common: NVMe/SSD for hot data, 10K/15K RPM SAS for performance-sensitive data, and LFF 7.2K drives (like UCS-HD1T7KL12G) for capacity and cold data. They serve as the economical capacity layer — suitable for bulk VM storage, backups, and large sequential read/write operations. Combining these drives into RAID 6 arrays or erasure-coded pools reduces rebuild risk and increases usable capacity while balancing cost.

RAID levels and resiliency

Typical RAID choices for this drive category include RAID 5 and RAID 6 for a balance of capacity and redundancy. RAID 6 is preferred in larger arrays because it protects against two concurrent disk failures during rebuild windows. For write-sensitive or small-block I/O heavy workloads, hardware RAID controllers with battery-backed (or supercapacitor) cache and appropriate stripe sizes will optimize performance. If using software RAID or distributed file systems, account for longer rebuild times associated with large LFF disks.

Comparison

SSD vs HDD tradeoffs

Compared with SSDs, the UCS-HD1T7KL12G provides far greater cost per gigabyte but lower random IOPS and higher latency. For read-heavy, small block, or latency-sensitive workloads, pair HDD capacity tiers with an SSD tier or use NVMe caching to optimize performance and cost. For pure capacity or sequential workloads (large backups, archives), LFF SAS drives remain cost-effective.

7.2K vs 10K vs 15K RPM

Higher RPM drives deliver better random IOPS and lower average access times at the cost of higher power, heat, and price. Evaluate workload profile: if random IOPS demand is low-to-moderate, 7.2K is a strong choice for capacity-oriented arrays. If latency or IOPS are critical, consider hybrid arrays or higher-RPM SAS drives.