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 (MZ-VLB256B) moves this 256GB class to a newer TLC V-NAND NVMe platform, delivering up to 3,500/2,200 MB/s and 240K/490K IOPS for noticeably faster boot, application launch, and scratch-disk response. Its 150 TBW endurance rating and 0.32 DWPD make it a stronger fit for OEM notebooks and compact workstations that need better write tolerance and more consistent client performance than earlier 256GB designs.

Endurance & Reliability

With an endurance rating of 150 TBW, this SSD can handle about 41 GB of host writes per day for 10 years, which is well above the write volume of a typical OS, office, or application drive. In practical terms, for normal client or embedded boot-drive workloads, it offers comfortable endurance headroom, while the 1.5 million hour MTBF further supports long-term operational confidence. Its UBER rating of 1.0E-15 means the drive is designed to maintain a very low rate of unrecoverable read errors, which is an important indicator of data-read reliability in day-to-day operation. This model does not include power-loss protection (PLP), so it is best deployed in systems with stable power or UPS support, where it can still provide dependable service for read-focused and moderate-write applications.

Technical Specs & Insights

1. The NVMe interface, paired with high sequential read bandwidth, accelerates large-block data movement so database snapshots, VM boot storms, and analytics datasets load far faster than with legacy SATA or SAS SSDs.
2. Its strong random read capability supports dense virtualization and transaction-heavy workloads by sustaining rapid access to small data blocks with less performance drop under concurrency.
3. The endurance profile is well suited for read-centric enterprise deployments such as content delivery, boot volumes, reference databases, and mixed-use infrastructure with moderate daily write pressure.
4. TLC V-NAND provides an effective balance of capacity, cost efficiency, and reliability, making it practical for scaling enterprise flash storage without the premium of write-optimized media.
5. The very low typical latency helps reduce application response time and tail-latency risk, which is especially valuable for real-time services, high-frequency lookup workloads, and performance-sensitive cloud platforms.

Capacity Sweet

Lower capacity reference: 128GB Higher capacity reference: 512GB Capacity positioning analysis: In this enterprise SSD family, the 256GB model sits at a practical sweet spot. Compared with the 128GB version, it provides noticeably better headroom for OS images, logs, metadata, and short-term workload growth, reducing the risk of early capacity pressure. Compared with the 512GB version, it preserves most of the same enterprise-class read/write and random IOPS behavior while keeping acquisition cost and overprovisioning budget under tighter control. It is especially well suited for small-to-mid virtualization clusters, such as hosting boot and utility volumes for roughly 25 to 40 virtual machines.

FAQ