345-BJNM Dell 30.72TB PCI-E Gen4.0 x4 NVMe SSD.

Essential Attributes of the Dell Enterprise SSD

This enterprise-class solid state drive is engineered for high-demand data center applications, offering exceptional storage volume and performance.

Primary Product Specifications

• Manufacturer Designation: Dell
• Model Identifier: 345-BJNM
• Device Classification: NVMe Solid State Drive
• Total Storage Volume: 30.72 Terabytes

Physical and Interface Characteristics

The drive utilizes a compact 2.5-inch small form factor with a 15mm z-height, designed for integration into dense server environments.

Interconnect Details

• Host Interface: PCI Express 4.0 x4
• Logical Interface: NVMe (Non-Volatile Memory Express)
• Flash Architecture: 144-Layer QLC (Quad-Level Cell) 3D NAND

Durability and Longevity Metrics

• Operational Shock Resistance: 1000G
• Mean Time Between Failures (MTBF): 2 million hours

Operational Performance Benchmarks

This SSD delivers remarkable speed for both sequential and random data access patterns, crucial for server workloads.

Sequential Transfer Velocities

• Maximum Read Bandwidth: 7,000 MB/s
• Maximum Write Bandwidth: 3,600 MB/s

Random Access Operation Speeds

• Random Read Performance: 800,000 IOPS (4K blocks)
• Random Write Throughput: 510 MB/s (64K blocks)

Compatibility and Integration

This U.2 drive includes a tray and is validated for use in Dell PowerEdge Server generations 14g through 17g, ensuring seamless deployment and reliability in supported infrastructure.

Dell 345-BJNM 30.72TB — Enterprise NVMe U.2 SSD Overview

The Dell 345-BJNM 30.72TB PCIe Gen4 x4 NVMe U.2 2.5" SFF Enterprise QLC 3D NAND SSD represents a high-capacity, high-density storage solution engineered for modern data centers and enterprise workloads that demand massive capacity, efficient power usage, and seamless integration with existing server infrastructures. Designed for U.2 (2.5") bays and optimized for PCI Express Gen4 performance, this drive is ideal for bulk storage, cold data tiers, archival pools, content repositories, and read-heavy analytics repositories.

Key Technical Highlights

Form factor & interface

The drive uses a standard 2.5-inch small form factor (SFF) with a U.2 connector, compatible with many Dell PowerEdge servers and third-party enterprise systems that accept U.2 NVMe modules. The PCIe Gen4 x4 NVMe interface delivers low-latency, high-throughput I/O capable of addressing modern server demands.

NAND type & capacity

Built from QLC (Quad-Level Cell) 3D NAND technology, this SSD stores four bits per cell, enabling extremely high areal density and the large 30.72TB capacity in a single 2.5" package. QLC's density advantage lowers cost per terabyte and simplifies capacity planning when consolidating storage.

Performance characteristics

Expect strong sequential read/write performance when interfacing over PCIe Gen4 x4, with throughput geared toward bulk transfers, large object serving, cold tier read operations, and sequential backup/restore jobs. Random I/O performance is optimized for read-dominant workloads and bursty traffic using internal caching and controller algorithms.

Endurance and reliability

QLC drives have lower program/erase (P/E) cycles per cell than TLC or SLC, so endurance ratings emphasize randomized write workloads and sustained write throughput. Dell's enterprise firmware and drive management features provide intelligent wear leveling, background garbage collection, and power-safe flushes to prolong service life and maintain data integrity.

Design Benefits and Use Cases

Capacity-dense storage pools

Replace multiple smaller drives with a single 30.72TB module to free up drive bays and simplify storage management. The high TB-per-slot ratio makes it an excellent fit for:

• Archive and backup targets
• Large object stores (media libraries, VOD content)
• Log retention and telemetry datasets
• Cold or warm tiers of multi-tier storage architectures

Cost-effective tiering strategy

Use QLC-based Dell 345-BJNM drives in a tiered storage model where hot transactional data remains on higher-end TLC or NVMe cache layers and capacity-centric datasets are offloaded to QLC tiers. This optimizes total cost of ownership (TCO) without sacrificing capacity or manageability.

Hyperscale and cloud environments

In hyperscale infrastructures or private clouds where maximizing capacity density and minimizing hardware expenditure are vital, these drives reduce the number of enclosures needed for the same amount of raw capacity, lowering facility and capital costs.

Performance Tuning & Best Practices

Optimize for read-heavy and sequential workloads

Because QLC performs best in read-dominant and sequential write scenarios, orient workloads accordingly:

• Primary storage for large sequential backups, object storage reads, and cold archives.
• Use a write-back cache tier (TLC-based NVMe or DRAM+NVDIMM) for bursty writes to protect QLC endurance.
• Leverage software-defined tiering that automatically migrates hot data to higher endurance drives.

Write amplification and alignment

Reduce write amplification by aligning file systems, using appropriate block sizes for the workload, and avoiding small, random write patterns when possible. Consider filesystem choices (XFS, ext4, ZFS with tuned settings) that minimize metadata churn on QLC tiers.

Thermal management and airflow

High-capacity NVMe drives in dense enclosures can generate heat. Ensure adequate chassis airflow, monitor drive temperatures, and adopt cool-down strategies for sustained heavy writes (throttling policies or thermal-aware scheduling).

Deployment Scenarios & Architecture Patterns

Cold-tier object storage appliance

Build a dense object store where each node uses multiple 30.72TB U.2 SSDs. Advantages include:

• Lower rack space and power per TB
• Fewer drive slots consumed by capacity compared to smaller SSDs or HDD racks
• Simplified rebuilds—large capacity with faster rebuilds over NVMe links than HDD-based racks

Backup target and snapshot repository

Use these drives as fast, compact repositories for backups and snapshots that must be both large and accessible for occasional restores. Pair with deduplication/compression-aware backup software to multiply effective capacity.

Hybrid flash-hdd architecture

Use the Dell 345-BJNM SSDs for warm/cold layers while keeping frequently updated hot data on higher-end TLC SSDs or persistent memory. The hybrid approach balances performance and cost while maximizing available capacity for bulk storage.

Capacity Planning & Sizing Guidance

Calculating effective capacity

When planning, account for RAID/erasure coding overhead, filesystem metadata, and compression/dedup ratios. Example considerations:

• RAID-6 with two-drive parity reduces usable capacity—factor in at procurement.
• Software compression and deduplication can increase usable space, but performance trade-offs may apply.
• Reserve a percentage of capacity (e.g., 10–20%) for over-provisioning to preserve performance and endurance.

Estimating endurance needs

Endurance is commonly expressed in TBW (terabytes written) or DWPD (drive writes per day). Use historical write metrics to estimate:

• Average daily written bytes per host or application
• Projected retention windows and churn
• Growth projections for future write rates

Because QLC has lower P/E cycles, allocate QLC drives to write-light or read-mostly tiers or protect them behind a write-optimized buffer.