WD launches long-life caching NVMe SSD for NAS disk drive boxes

Western Digital has launched an SSD tailored for acting as a cache in disk drive-based network-attached storage arrays and so speeding them up.

Red is WD’s drive brand for NAS products. The Red SN700 SSD is a long-life drive in the M.2 gumstick card format with 250GB, 500GB, 1TB, 2TB and 4TB capacity levels. It follows on from 2019’s Red SA500 SATA SSD with its 500GB to 4TB capacity range, and is much, much faster as well as having a doubled endurance rating.

The SN700 is rated as a 24×7 operation drive and its endurance makes it suitable for NAS use with much reading and writing of data. The Red SA500 came in both 2.5-inch and M.2 formats, but the SN700 is M.2 only.

WD is being coy about the type of flash inside the SN700. We know the SA500 used BiCS 3 generation 3D NAND, 96-layer TLC flash, but WD is now shipping BiCS 4 96-layer product and foundry partner Kioxia has announced BiCS 5 176-layer products.

Tamblyn Calman, sales and marketing director at QNAP, provided a quote for WD: “The WD Red SN700 NVMe SSD helps to further enhance the QNAP product portfolio’s storage capabilities by boosting the NAS system’s read/write speeds without adding to the overall number of disks in the array.”

Here is WD’s performance table for the SN700:

It’s roughly similar to WD’s existing Black SN750 M.2 format SSD aimed at the PC gaming market and announced in January 2019. 

Here, for reference, is our filed data for the SA500:

The SN700 is around five times faster than its SATA predecessor. The endurance numbers equate to one drive write per day (DWPD) for the 250GB, 500GB and 1TB capacity models but 0.7 DWPD for the 2TB and 4TB product.

Competitor Seagate, which ships IronWolf disk drives into the NAS market, has its own IronWolf 510 SSD. This is also an M.2 format product with lower capacity and performance earnings than the SN700. It has a smaller maximum capacity of 1.92TB and lower performance across its NVMe interface: 380,000/28,000 random read/write IOPS, 3.15GB/sec sequential read and 1GB/sec sequential write. Its endurance is on a par with the SN700 at 1DWPD.

SN700 pricing ranges from $65 for the 250GB model up to $650 for the 4TB product.