Western Digital WD_BLACK SN770 2000GB

The Western Digital WD_BLACK SN770 2000GB represents a mature iteration of Western Digital’s vertically integrated, proprietary NVMe architecture. The drive utilizes an in-house SanDisk 20-82-10081-A1 controller paired with Kioxia/WD BiCS5 112-layer 3D TLC NAND. This architecture is DRAM-less, relying instead on a robust Host Memory Buffer (HMB) implementation to cache the logical-to-physical mapping tables in system RAM, a design choice that reduces physical footprint and power consumption while maintaining high burst performance. Hardware analysis indicates that the SN770 is power-efficient with excellent thermal management, rarely exhibiting significant thermal throttling in standard airflow environments, making it viable for laptops and ultra-thin builds; it supports Western Digital’s Game Mode (disabling low-power states to minimize latency), and the 2TB model maintains high sustained write speeds until the pseudo-SLC cache is saturated, after which write performance falls to native TLC speeds.

Key Specifications

• Interface: PCIe 4.0 x4 (NVMe 1.4)
• Sequential Read/Write: 5,150 MB/s / 4,850 MB/s
• Controller: SanDisk 20-82-10081-A1 (4-channel, Proprietary)
• NAND Flash: Kioxia/WD BiCS5 112-Layer 3D TLC
• DRAM Cache: None (HMB Support)
• Endurance: 1200 TBW
• Physical Layout: Single-sided M.2 2280 PCB
• Encryption: No hardware-based AES encryption (TCG Pyrite only)

Hardware Alternatives

• Western Digital Blue SN580 2000GB: Serves as a direct architectural relative within the WD stack, utilizing similar controller technology and BiCS5 NAND but running at reduced clock speeds with restrictive firmware caps, effectively acting as a detuned version of the SN770.
• Samsung 980 2000GB: A conceptual competitor as a DRAM-less, in-house NVMe solution, though the SN770 uses the faster PCIe 4.0 interface compared to the 980's PCIe 3.0 limitation.
• Maxio MAP1602 drives (e.g., Lexar NM790 2000GB): Represent the primary third-party controller competition; while many MAP1602 drives utilize newer 232-layer NAND for higher peak throughput, they are compared to the SN770 due to similar DRAM-less, high-efficiency design philosophies.