WD Black SN7100 - M.2 PCIe Gen4 NVMe SSD - 1TB

The WD Black SN7100 is the successor to the SN770, built on Kioxia 218-layer BiCS8 TLC NAND and the SanDisk Polaris 3 controller. Sequential reads reach up to 7,250 MB/s and writes up to 6,900 MB/s on the 1TB and 2TB models, pushing close to the PCIe Gen 4 x4 ceiling. Available in 500GB through 4TB.

DRAM-less Design

Like its predecessor, the SN7100 uses a DRAM-less architecture with Host Memory Buffer (HMB) instead of onboard DRAM. This reduces power consumption without sacrificing random I/O performance for typical consumer workloads. The nCache 4.0 SLC caching layer provides write burst headroom.

Power Efficiency

The DRAM-less design and efficient Polaris 3 controller deliver up to 100% better power efficiency compared to the SN770. Active power sits around 3W, making this a strong option for laptops and compact builds where thermals matter.

SN7100 vs. SN770

The SN7100 brings higher sequential speeds (7,250 vs 5,150 MB/s read), newer 218-layer NAND (vs 112-layer), and a 4TB capacity option the SN770 lacked. Random IOPS are also significantly improved (1,000K vs 740K read on 1TB). If you already own an SN770, the upgrade only matters for large sequential transfers; for gaming and general use, the difference is marginal.

Best for: Gaming PCs, content creation, and laptop upgrades where PCIe Gen 4 performance and low power consumption are priorities.

Avoid if: You need PCIe Gen 5 speeds (see SN8100) or a DRAM-cached drive for sustained heavy writes.