General

Brand	Samsung
Model	SM841 (840 PRO Series)
Capacity	256GB
Usage Class	Client

Interface

Host Interface	SATA
Total Interface Bandwidth	6 Gb/s

Physical Dimension

Form Factor	2.5

Flash & Endurance

NAND Flash	MLC
Drive Writes Per Day	0.3
Total Bytes Written	73 TBW

Performance

Sequential Read	540 MB/s
Sequential Write	520 MB/s
Random Read IOPS	100000
Random Write IOPS	90000
Average Latency	50 μs

Reliability

Mean Time Between Failures	1.5 Million Hours
Uncorrectable Bit Error Rate	1.0×10⁻¹⁷
Power Loss Protection	No

Part Number

MPN

Engineer's Note

The Samsung SM841 MZ7PD256HAFV-0BW00 is best suited for read-intensive virtualization boot pools, database log/metadata tiers, and CDN edge cache nodes that need near–SATA-limit throughput at 540/520 MB/s and up to 100K/90K IOPS without moving to a higher-cost interface. Its MLC NAND gives it a durability and latency-consistency advantage over typical same-capacity TLC SATA drives, making it a stronger choice for enterprise client and light mixed-workload deployments within a 0.3 DWPD, 73 TBW envelope.

Endurance & Reliability

With an endurance rating of 73 TBW and 0.3 DWPD, this 256 GB SSD is well suited for typical read-heavy client and light enterprise workloads, such as OS boot, application hosting, and general office or embedded system use. In practical terms, that level of endurance is more than sufficient for a system drive under normal daily write volumes and can comfortably support many years of stable operation when not used for write-intensive logging or database workloads. Its specified UBER of 1.0E-15 means the drive is designed for a very low rate of unrecoverable bit errors, supporting dependable data reads in standard operating environments, while the 1.5 million-hour MTBF further reflects strong overall hardware reliability. This model does not include power-loss protection, so it is best deployed in systems with stable power or upstream backup power, but for procurement of non-write-critical boot or application drives, it remains a solid and dependable choice within its intended use profile.

Technical Specs & Insights

1. The SATA interface ensures broad compatibility with legacy enterprise servers and storage arrays, enabling straightforward upgrades without changing the existing backplane or controller architecture.
2. Its sequential read performance is well suited for fast boot, image loading, and efficient delivery of large files in read-focused enterprise workloads.
3. Strong random read capability helps virtualized environments and transactional applications respond faster under heavily mixed access patterns.
4. The endurance profile is optimized for read-intensive deployments, making it a cost-effective fit for boot drives, content delivery, and analytics tiers with limited daily writes.
5. MLC NAND provides a balanced combination of reliability, consistency, and lifecycle stability that enterprise buyers expect from datacenter-grade SATA SSDs.

Capacity Sweet

Reference capacities in the same series for MZ7PD256HAFV-0BW00 are: Lower capacity: 128GB Higher capacity: 512GB Typical positioning in this series: 128GB: broadly similar enterprise SATA performance, with sequential read/write and random IOPS in the same general class as the 256GB model 256GB: same performance class, but with better usable headroom for OS, logs, and application growth 512GB: similar baseline performance profile, mainly adding more capacity rather than a dramatic performance jump Capacity positioning analysis: Within this series, the 256GB model is the practical sweet spot. Compared with the 128GB version, it gives much better space flexibility for operating systems, patches, logs, and moderate data growth, reducing the risk of early capacity pressure. Compared with the 512GB option, it delivers a better balance between acquisition cost and usable capacity while staying in the same enterprise performance tier. It is well suited for small to mid-size virtualization clusters, such as hosting boot and utility volumes for about 30 to 50 business application VMs.

FAQ