Western Digital WD Green 250GB

The Western Digital WD Green SN350 (250GB) is an entry-level client NVMe drive built on a proprietary, DRAM-less architecture developed by Western Digital/SanDisk. It uses a scaled-down controller likely related to the SN550/SN570 series and high-density 3D QLC NAND. The drive relies on Host Memory Buffer (HMB) technology and a static pseudo-SLC cache to reach its rated sequential throughput. Hardware analysis indicates the 250GB SKU has a notably low endurance rating compared to TLC-based peers. The SLC cache is relatively small; once exhausted, write speeds drop significantly as the controller writes directly to QLC, so the drive is optimized for read-heavy, light-duty applications rather than write-intensive OS or content-creation workloads.

Key Specifications

• Interface: PCIe 3.0 x4 (NVMe 1.3/1.4 compliant)
• Controller: Proprietary SanDisk/WD (DRAM-less)
• NAND Configuration: 3D QLC (BiCS architecture)
• Max Sequential Read: 2400 MB/s
• Max Sequential Write: 1500 MB/s
• Form Factor: Single-sided M.2 2280

Hardware Alternatives

• Western Digital Blue SN570: The direct upstream architectural relative that uses similar controller logic but upgrades NAND to TLC for higher sustained write performance and endurance.
• Crucial P3: A segment competitor using Micron QLC NAND and a Phison DRAM-less controller; shares high burst speeds with steep performance drop-offs during sustained transfers.
• Kingston NV2 250GB: Operates in the same entry-level tier but uses a variable bill of materials, oscillating between Phison and SMI controllers, whereas the WD Green maintains a consistent proprietary controller design.