Western Digital today introduced a new flash-enhanced hard-drive architecture, dubbed OptiNAND technologyk, which optimizes and integrates hard disk drives (HDDs) with an iNAND embedded flash drive. According to WD, OptiNAND increases areal density without the need for additional drive heads or disks, and improves drive capacity, performance, and reliability.
Breathing New Life Into the Venerable Spinning Hard Drive
In this age of hyper-fast SSDs, traditional spinning hard drives are often overlooked, but their high storage capacity and low cost per gigabyte help them retain a central role, particularly in the business world. IDC, which tracks technology trends, projects that in 2025, HDDs will represent 82% of capacity sold to the enterprise market.
Investments in HDD technology remain critical to supporting worldwide data growth, so WD developed OptiNAND technology by integrating its NAND flash with its HDDs. OptiNAND integrates an iNAND Universal Flash Storage Embedded Flash Drive (EFD) with traditional spinning disk media, and incorporates changes to the firmware algorithm and system-on-a-chip (SoC).
The HDD-Flash Mashup: Lower Cost, Faster Access
Before OptiNAND, non-volatile memory in an HDD was used primarily for booting and storing tiny amounts of metadata. As HDD storage architecture has become more sophisticated, the addition of a flash layer is a logical step in the system’s memory hierarchy. Flash is more cost-effective than DRAM, with data persistence across power cycles. Flash also provides faster access than disk, enabling time-sensitive calculations to be performed while keeping the disk free to perform host operations.
The new OptiNAND-enabled memory hierarchy utilizes the drive SoC to control communication with the iNAND EFD. With OptiNAND, key drive housekeeping functions can take advantage of an increase in metadata capability.
During an emergency power off event, OptiNAND can flush more than 100MB of write cache data into iNAND while prior-generation HDDs could only flush ~2MB of data to serial flash, representing a 50-fold increase in customer data retention.
20TB OptiNAND-Enhanced Drives On Deck
So far, WD has sent OptiNAND-enhanced drive samples to select customers, and eventually plans to implement this technology across its enterprise portfolio. The first generation of products with OptiNAND delivers 20TB capacity in a nine-disk platform (2.2TB/platter) with CMR recording format.
