Although NAND memory has replaced traditional hard disk drives in the vast majority of client PCs, HDDs can still offer capacities at costs not achievable by solid-state drives today, particularly in the data center space. In a bid to retain the relevance of hard drives for years to come, Western Digital on Tuesday announced two distinct families of HDDs: one aimed at applications that require maximum performance and decent IOPS-per-TB, another designed for power-optimized applications that value limited power consumption and predictable performance.
High-Bandwidth HDD
The whole concept of Western Digital's High-Bandwidth HDD stems from reading data from the media using more than one head and transferring it to one or two hosts. The company showcases two types of High-Bandwidth HDDs at its Innovation Day: one uses more than one head for reading and writing at the same time to achieve 2X bandwidth compared to conventional HDDs, and another one features a second fully independent actuator to achieve 2X bandwidth and 2X sequential I/O performance. Over time, High-Bandwidth HDDs are projected to scale up bandwidth by eight times and I/O by four times when both approaches are combined within a single HDD.
Image 1 of 3 (Image credit: Western Digital) (Image credit: Western Digital) (Image credit: Western Digital)
WD's original dual-actuator High-Bandwidth HDD architecture — which is already being validated by the company's clients — allows multiple heads on multiple tracks to read and write simultaneously, thus exploiting internal parallelism to deliver 2X bandwidth of traditional 3.5-inch HDDs.
The next step for Western Digital is its Dual-Pivot High-Bandwidth HDD architecture is to add a second, fully independent actuator on a separate pivot inside the same 3.5-inch drive. Each actuator controls its own set of heads and enables two independent read/write operations at once, thus delivering up to 2X sequential I/O performance without reducing capacity. Dual-Pivot HDDs are currently in the lab and are targeted to become available in 2028. Over time, the two architectures will be combined to deliver 4X higher I/O performance compared to traditional hard drives.
Power-Optimized HDDs
In addition to offering High-Bandwidth drives for performance-demanding applications, Western Digital is also working on Power-Optimized HDDs that reduce power consumption by 20% for 'active cold' storage tier.
Western Digital positions Power-Optimized HDDs for 'active cold' storage tier for AI workloads that generate massive volumes of data — such as datasets, checkpoints, and logs — which must remain quickly accessible (which rules out tape), but cannot be stored on traditional high-capacity HDDs or SSDs due to cost concerns.
The company says that these power-optimized 3.5-inch HDDs use a 'minimal random IO' for 20% less power than conventional drives, which reduces ownership costs and makes 'active cold' storage cheaper to run. WD expects the first power-optimized HDDs to enter customer qualification in 2027.
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