General

Brand	Samsung
Model	PM981a
Capacity	256GB
Usage Class	Client

Interface

Host Interface	NVMe
Total Interface Bandwidth	32 Gb/s

Physical Dimension

Form Factor	M.2 2280

Flash & Endurance

NAND Flash	TLC V-NAND
Drive Writes Per Day	0.32
Total Bytes Written	150 TBW

Performance

Sequential Read	3500 MB/s
Sequential Write	2200 MB/s
Random Read IOPS	240000
Random Write IOPS	490000
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	MZVLB256HEHQ

Engineer's Note

Compared with the previous-generation MZVLB256HEHQ, the Samsung PM981a MZVLB256HBHQ delivers a more refined 256GB client NVMe profile with 3,500/2,200 MB/s sequential performance and up to 240,000/490,000 IOPS, giving it a clear edge in OS boot, application launch, and write-intensive workstation responsiveness. Its TLC V-NAND design, 150 TBW endurance, and 0.32 DWPD rating make it a stronger choice than its predecessor for OEM notebooks and compact desktops that need higher sustained write behavior and dependable lifecycle efficiency in a low-capacity NVMe tier.

Endurance & Reliability

With an endurance rating of 150 TBW and 0.32 DWPD, the MZVLB256HBHQ-000H1 is well suited for typical client and light-duty boot-drive workloads, including OS, office applications, web access, and general business use. In practical terms, this level of endurance is usually more than sufficient for a system drive over many years of normal operation, and in common desktop usage it can comfortably support around a decade of everyday write activity. From a reliability perspective, the drive is specified at 1.5 million hours MTBF and an UBER of 1.0E-15, meaning the expected uncorrectable bit error rate is extremely low and aligned with standard high-quality SSD operation. This model does not include power loss protection, so it is best deployed in systems with stable power or UPS coverage rather than write-critical environments where sudden power interruption protection is required.

Technical Specs & Insights

1. The NVMe interface removes legacy storage bottlenecks, enabling modern servers to feed CPUs and virtualized workloads with far higher parallelism and faster response.
2. Its strong sequential read performance accelerates bulk data access, reducing startup time for databases, analytics jobs, and large-scale application loading.
3. The high random read capability supports dense transactional workloads, helping VMs, metadata-heavy applications, and read-intensive databases maintain smooth multi-user performance.
4. With a light write-endurance profile, this drive is best aligned with read-centric enterprise deployments such as boot volumes, content delivery, and reference-data tiers rather than heavy write logging.
5. TLC V-NAND combined with very low typical latency delivers a balanced mix of cost efficiency, capacity density, and consistently fast access for latency-sensitive cloud and enterprise platforms.

Capacity Sweet

Lower capacity reference: 128GB (MZVLB128HAHQ-000H1) Higher capacity reference: 512GB (MZVLB512HAJQ-000H1) Typical same-series performance reference: 128GB: up to ~3,000 MB/s read, ~900 MB/s write; up to ~270K/250K random read/write IOPS 256GB (current): up to ~3,000 MB/s read, ~1,150 MB/s write; up to ~270K/300K random read/write IOPS 512GB: up to ~3,200 MB/s read, ~1,800 MB/s write; up to ~330K/300K random read/write IOPS Capacity positioning analysis: The 256GB model sits at the sweet spot in this series. Compared with the 128GB version, it offers much better space flexibility for OS images, logs, patch growth, and application headroom, reducing early capacity pressure. Compared with the 512GB version, it keeps acquisition cost lower while still delivering very similar everyday read/write behavior for typical enterprise workloads. This makes 256GB a balanced choice for mid-scale deployments, such as boot and utility storage for around 40 to 60 virtualization hosts or edge nodes.

FAQ