Western Digital WD Green 240GB

The Western Digital WD Green 240GB is an entry-level SATA solution built around a DRAM-less architecture to minimize power consumption and physical footprint. The drive typically pairs a Silicon Motion SM2258XT (or a proprietary SanDisk equivalent) controller with SanDisk 3D TLC NAND, though component sourcing varies by production batch. Without a dedicated DRAM cache buffer, the drive relies on the controller’s on-die SRAM and a pseudo-SLC caching strategy to maintain burst performance. This architecture prioritizes low-queue-depth read operations, making it suitable for basic OS loading but susceptible to performance drops during sustained heavy workloads. Field notes indicate the WD Green series employs aggressive Link Power Management (LPM) settings, which aids power efficiency for laptops but has been associated with minor latency or "stuttering" on some older desktop chipsets during wake states. Owing to the small capacity of the SLC cache on the 240GB model, write speeds can sharply decline—often falling below mechanical HDD speeds—once a large transfer saturates the cache. It is commonly regarded as a read-focused drive, not ideal for write-intensive applications or as a primary workstation drive.

Key Specifications

• Interface: SATA III 6Gb/s
• Sequential Speeds: Up to 545 MB/s Read / 465 MB/s Write
• Controller: Silicon Motion SM2258XT / SanDisk Proprietary (DRAM-less)
• NAND Flash: SanDisk 3D TLC (Legacy units may use Planar TLC)
• Endurance: ~80 TBW (Terabytes Written)
• Form Factor: 2.5" / 7mm (Single-sided PCB design)
• Features: SLC Caching, DEVSLP (Device Sleep) support, S.M.A.R.T. support

Hardware Alternatives

• SanDisk SSD Plus: Internal hardware sibling to the WD Green; following Western Digital's acquisition of SanDisk, these product lines often share identical bills of materials, including controller and NAND packages, offering virtually indistinguishable real-world performance.
• Kingston A400 240GB: A direct architectural competitor in the DRAM-less SATA segment, typically using a Phison S11 controller with similar burst performance and limited sustained write performance due to the lack of DRAM buffering.
• Crucial BX500 240GB: Comparable in tier and application, also using a DRAM-less design (often Silicon Motion SM2259XT), but differentiated by Micron’s native 3D NAND which can offer different endurance characteristics compared to the SanDisk BiCS flash used in the WD Green.