General

Brand	Samsung
Model	840 PRO
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	0.16
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	MZ7PC256HAFV

Engineer's Note

The Samsung 840 PRO 256GB (MZ7PD256HCGM) is a strong upgrade from the MZ7PC256HAFV, delivering up to 540/520 MB/s sequential throughput and 100,000/90,000 IOPS random performance for noticeably faster transactional and mixed-workload response on the same SATA interface. Its MLC NAND and 73 TBW endurance make it a more durable choice than typical client-grade SATA SSDs in its class, especially for write-intensive workstation, boot-volume, and read-cache deployments that need consistent low-latency performance.

Endurance & Reliability

With an endurance rating of 73 TBW and 0.16 DWPD, the MZ7PD256HCGM is well suited for light to moderate write workloads such as OS boot, application hosting, and general-purpose office or embedded system use. In practical terms, this level of endurance is typically more than sufficient for a system-drive role over many years, provided the workload is not heavily write-intensive. For reliability, the drive is rated at 1.5 million hours MTBF and an UBER of 1.0E-15, meaning the expected unrecoverable read error rate is extremely low and aligned with standard enterprise SSD expectations. This model does not include power-loss protection, so while it is dependable for stable-power environments, applications with frequent unexpected outages or in-flight write protection requirements should use a platform with UPS support or a drive with PLP.

Technical Specs & Insights

1. The SATA interface makes this drive easy to deploy in legacy enterprise servers and storage arrays, enabling cost-effective upgrades without changing the existing backplane or controller architecture.
2. Its sequential read performance is well suited for boot volumes, virtual machine image access, and read-heavy application delivery where steady data streaming improves system responsiveness.
3. Strong random read capability helps accelerate transactional databases, VDI environments, and metadata-heavy workloads by reducing storage wait time under concurrent access.
4. The modest endurance rating indicates it is best aligned with read-centric enterprise use cases such as OS drives, caching tiers, and content serving rather than sustained write-intensive logging or analytics.
5. MLC NAND combined with very low typical latency delivers more consistent enterprise-grade response times, supporting predictable performance for latency-sensitive business applications.

Capacity Sweet

For Samsung MPN MZ7PD256HCGM (256GB), the nearest lower capacity in the same family is typically 128GB, while the next higher capacity is 512GB. In this lineup, 256GB is the sweet-spot option: it gives noticeably more headroom than 128GB for OS growth, logs, patches, and overprovisioning, while avoiding the higher acquisition cost of 512GB when extra capacity is not yet required. Because sequential throughput and random IOPS are broadly similar across these tiers, 256GB delivers the best cost-performance balance for mid-scale deployments, such as a 12- to 16-node virtualization cluster boot tier.

FAQ