Western Digital Introduces WD Red SN700: PCIe 3.0 M.2 NVMe SSDs for NAS Systems

Western Digital’s Red series of drives for network-attached storage systems has a significant share in various NAS market segments. The series started off with a focus on hard drives, and more recently WD Red SSDs were introduced in Q4 2019, a few years after the SanDisk acquisition. These SATA SSDs (in both 2.5″ and M.2 form-factors) were based on Marvell 88SS1074 controllers and targeted caching applications.

The increasing popularity of tiered storage, coupled with the deployment of NVMe (in the form of add-in cards, and now, natively in NAS boards) has prompted Western Digital to create a new member in the WD Red family. The new WD Red SN700 comes in 5 capacities ranging from 250GB to 4TB.

WD Red SN700 NVMe SSDs for NAS

Capacity
250 GB
500 GB
1 TB
2 TB
4 GB

Model Number
WDS250G1R0C
WDS500G1R0C
WDS100T1R0C
WDS200T1R0C
WDS400T1R0C

Controller
SanDisk In-House?

NAND Flash
3D TLC NAND

Form-Factor
Interface
M.2-2280, PCIe 3.0 x4, NVMe 1.3

Single-Sided
(22.15mm x 80.15mm x 2.38mm)
Double-Sided
(22.15mm x 80.15mm x 3.58mm)

Seq. Read Max
(128KB @ QD32)
3100 MBps
3430 MBps
3400 MBps

Seq. Write Max
(128KB @ QD32)
1600 MBps
2600 MBps
3000 MBps
2900 MBps
3100 MBps

Rand. Read IOPS
(4KB @ QD32)
220K
420K
515K
480K
550K

Rand. Write IOPS
(4KB @ QD32)
180K
380K
560K
540K
520K

SLC Caching
Yes

DRAM Buffer
?
?
?
?
?

Opal Encryption
?

Power
Peak
9.24 W

PS3 (LP)
70 mW
100 mW

PS4 (Sleep)
3.5 mW
5 mW

Warranty
5 years

MTBF
1.75 million hours

TBW
500
1000
2000
2500
5100

DWPD
1
0.7

Addl. Info.
Link

MSRP
?
?
?
?
?

A PCIe 3.0 x4 NVMe drive can provide a quantum leap in I/O performance, especially over pure HDD-based systems. NAS units are fast becoming hyperconverged application servers, and NVMe drives can improve user experience with both storage tasks as well as application tasks. In particular, tasks related to workloads like virtualization, multi-user collaborative editing and other similar applications. The benefits for traditional enterprise workloads such as intensive databases are also evident, even when the NVMe drive is used purely as a caching drive. Interestingly, the 1TB and lower capacity models have a 1 DWPD rating, while the 2TB and 4TB ones have a 0.7 DWPD endurance number.

It must be noted that Seagate has already released two generations of NVMe drives for the NAS market in their IronWolf series. WD is playing a bit of a catch-up in this particular market segment, but its SanDisk heritage and vertical integration can possibly give the WD Red SN700 an edge over the IronWolf series.