In response to heated criticism for not disclosing that some of its hard drives use slower SMR technology, WD penned a blog post outlining its plans to release a new line of WD Red Plus drives that use standard conventional magnetic recording (CMR) tech as an alternative to its slower SMR drives.
WD's change in course comes after widespread criticism from its customers about its surreptitious use of slower shingled magnetic recording (SMR) technology in some of its hard drives without disclosing that fact in marketing materials or specification sheets. Those claims of false advertising touched off a wave of class-action lawsuits, with one even calling for a ban to block WD from selling SMR drives for NAS usage.
WD previously disclosed to Tom's Hardware that the 2 to 6TB WD Red hard drives, among others, use SMR technology. This tech boosts capacity and results in a lower manufacturing cost, but it comes at the expense of performance, particularly in random write activity. Among the generally slower performance, that can also cause excessive rebuild times (resilvering) in the targets NAS use cases, particularly if they use ZFS RAID arrays.
WD's announcement outlines a new series of WD Red Plus drives that come with the standard CMR technology, but in the same 2 to 6TB capacity points as the slower SMR drives. WD positions the new Red Plus drives for its customers with more demanding needs, particularly in the SOHO and SMB segment, that need better performance with ZFS RAID arrays.
WD will continue shipping the 2 to 6TB WD Red drives with DM-SMR (Drive-Managed SMR) for less-demanding SOHO users, with the existing CMR WD Red drives being moved to the WD Red Plus line to create a split product stack. The WD Red Pro line remains unchanged with CMR drives.
WD has started listing its existing hard drives with SMR technology in marketing materials, and retailers have updated product listings. For some impacted customers, the company is also replacing SMR drives with faster CMS models. Still, WD will have to be clear with the new drive positioning to avoid confusion among less tech-savvy customers that could seek out the WD Red family as a value alternative while not fully understanding SMR's impact on performance.
WD's blog post says SMR is still effective in some use-cases but acknowledges it can lead to performance problems:
"As explained in our post on DMSMR, as well as in media reviews, these drives prefer idle time to perform background operations, without which the drive may take longer to complete a command. Our use-case analysis shows that SOHO workloads typically are based on short periods of access to the drives.
[...]In a RAID rebuild scenario using a typical Synology or QNAP (non-ZFS) platform, WD Red DMSMR drives perform as well as CMR drives or show slightly longer RAID rebuild times, depending on the condition of the drive and extent of rebuild required. While test results can vary from one methodology and test bed to the next, we acknowledge that in some cases DMSMR, for the idle-time reasons covered earlier, can result in slower rebuild times."
SMR does result in slower performance than normal hard drives in a multitude of use-cases, but the company only acknowledges the functional problems with RAID arrays. It doesn't address the impact in standard desktop PCs, like the SMR-powered WD Blue and WD Black SMR drives the company ships. Given that these drives haven't suffered from compatibility issues, it isn't clear if WD will replace or complement those drives with faster CMR models.
The company also says it is working with iXsystems to developed new ZFS-worthy drives with slower SMR technology:
"The explosion of data seen today has spawned a spectrum of NAS uses cases, as well as increasingly demanding applications. One of those includes use of ZFS, an enterprise-grade file system. The increased amount of sustained random writes during ZFS resilvering (similar to a rebuild) causes a lack of idle time for DMSMR drives to execute internal data management tasks, resulting in significantly lower performance reported by users. While we work with iXsystems on DMSMR solutions for lower-workload ZFS customers, we currently recommend our CMR-based WD Red drives, including WD Red Pro and the forthcoming WD Red Plus."
Meanwhile, both Seagate and Toshiba have also admitted to shipping SMR drives without full disclosure, but those drives are targeted for desktop PC use, and not for NAS usage. Still, we've yet to hear a response from those companies on any planned changes to their respective product stacks, nor have we seen signs of legal activity like the class-action lawsuits lodged against WD.