Western Digital Red SN700 NVMe NAS SSD review
1DWPD/2000TBW 1TB, M.2 NVMe at 3430MB/sec
Western Digital’s latest NVMe SSD is intended to broaden out the company’s product lineup, but it also starts to end their SATA solid-state drives (SSDs). Recent releases from WD include the all-new WD Red SN500 (not Blue), which serves as a companion product for NAS units with increased endurance rated 1DWPD, that’s 2TBW for the 1TB model. Western Digital (WD) has divided its eponymous internal solid-state drives (SSDs) into six easily distinguishable categories. Performance is taken care of by various fast drives under the Black umbrella, enterprise by Gold, surveillance by Purple, mainstream models assemble under Blue, entry-level models assemble under Green, and Red is appreciated by PC aficionados but now aimed at soho solutions.
The SN700 RED however is intended particularly for use with network-attached storage (NAS) systems, and it places a strong emphasis on consistent performance and long-term reliability and .. endurance. The SATA-based SA500 (2.5in or M.2), available in capacities of 500GB, 1TB, and 2TB, had been Red’s sole SSD competitor up until recently. Red SN700 M.2 NVMe solutions now include SSDs ranging in capacity from 250GB to 4TB. WD’s SN700 drives are designed to work with premium NAS boxes that employ NVMe M.2 SSDs for caching purposes. However, the company isn’t particularly clear about the technology behind the drives. You can see close similarities to those of the WD Black SN750 series, which was introduced in early 2019. Those Black drives were the pinnacle of performance at the time, but they have since been surpassed by PCIe Gen x4 models that have twice the sequential and IOPS performance.
So yeah, what distinguishes these RED NAS-specific drives from regular Black or Blue hard drives? Well, the 2,000 TBW rating on this PCIe 3.0 x4 1TB device is significantly higher than the 600 TBW rating on the SN750 model with the same capacity. The close to threefold increase is critical in the context of where the SSD is used, in this case, always-on NAS boxes. As such the SSD is rated at more than one full drive write per day (DWPD) throughout the course of the SSD’s warranty period of five years. And that is an exemplary basis of endurance. WD employing technology that’s quite similar to that found on the SN750, even though the controller, which is labeled SanDisk 20-82-000705-A2, is a slight derivation of the SN750 model. Of course, TLC NAND is used (we expect 64 layers). It’s been a while since Western Digital reinvigorated its Red NAS-optimized hard drives. On paper, the Red SN700 series appears to have everything going for it and the pricing ain’t bad but not super either at 170 EUR for the 1 TB model, roughly 17~18 cents per GB with that 2,000 TBW rating as well as 3 GB/sec and higher performance on both reads and writes.
WD Red SN700
WD In-house (SanDisk)
SanDisk TLC (three bits per cell))
PCIe Gen 3 x4
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Please do understand that prices fluctuate each day.
We do have some reservations about the relatively delayed release of a PCIe Gen 3 SSD for NAS, given that the transition to PCIe Gen 4 in NAS is already getting underway. WD Red SN700 SSD, on the other hand, is an excellent choice if you want to add cache to your NAS in 2021 (as well as scaling up random performance or your storage pools in an older system), and it does exactly as advertised at proper performance.