Western Digital PC SN720
PCIe M.2 · PCIe 3.0 x4, NVMe 1.3 · WD in-house
Specifications
| Interface | PCIe 3.0 x4, NVMe 1.3 |
|---|---|
| Controller | WD in-house |
| NAND Type | Kioxia/SanDisk BiCS3 (64L TLC) |
| DRAM Cache | Yes |
| Warranty | 5 years |
| Seq Read | 3,000 MB/s |
|---|---|
| Seq Write | 1,600 MB/s |
| Rand Read | 225,000 IOPS |
| Rand Write | 185,000 IOPS |
| Endurance | 200 TBW |
| Part Number | SDAPNTW-256G |
| Seq Read | 3,400 MB/s |
|---|---|
| Seq Write | 2,400 MB/s |
| Rand Read | 400,000 IOPS |
| Rand Write | 330,000 IOPS |
| Endurance | 300 TBW |
| Part Number | SDAPNTW-512G |
| Seq Read | 3,400 MB/s |
|---|---|
| Seq Write | 2,800 MB/s |
| Rand Read | 500,000 IOPS |
| Rand Write | 400,000 IOPS |
| Endurance | 400 TBW |
| Part Number | SDAPNTW-1T00 |
| Seq Read | 3,400 MB/s |
|---|---|
| Seq Write | 2,800 MB/s |
| Rand Read | — |
| Rand Write | — |
| Endurance | 500 TBW |
| Part Number | SDAPNTW-2T00 |
Overview
Released in 2018, the Western Digital PC SN720 is a high-end NVMe solid-state drive (SSD) designed for OEM and client computing applications. It is similar to the PC SN730 successor WD Black SN750, but uses BiCS3 NAND instead of BiCS4, resulting in slightly lower performance.
Technical Specifications
The PC SN720 uses the PCIe Gen3 x4 interface with NVMe 1.3 protocol, delivering sequential read speeds up to 3,400 MB/s and sequential write speeds up to 2,800 MB/s in its highest capacity configurations.
Controller & Cache
The PC SN720 is based on Western Digital's first in-house controller, likely a variant of the 8-channel "Triton MP28" controller found in the SN730, but paired with 64-layer BiCS3 flash memory. A DDR4 DRAM cache is included, and the drive also employs a dynamic pseudo-SLC cache that writes to SLC (single-level cell) blocks for improved performance. The SLC cache size is is not officially disclosed but is typically variable depending on capacity.
NAND Type
What mainly sets the SN720 apart from the SN730 and SN750 is the BiCS3 (Bit Cost Scaling 3rd generation) NAND, developed by Western Digital/SanDisk and Kioxia (formerly Toshiba). This 64-layer 3D TLC (Triple-Level Cell) NAND operates at bus speeds of 400-533 MT/s.