Fadu’s FC5161 SSD Controller Unveiled in Western Digital’s PCIe Gen5 Enterprise Drives

Earlier this year, Western Digital introduced its Ultrastar DC SN861 SSDs with minimal fanfare about the controller technology powering them, leading many to assume WD was using its own designed controller. However, a recent investigation has revealed that the company opted for a controller from Fadu—a company from South Korea, founded in 2015, known for crafting high-quality SSD solutions for enterprise use.

The Ultrastar DC SN861 is specifically designed for datacenters and enterprises that demand high-performance storage and are transitioning to PCIe Gen5 devices. As shown in photos by Storage Review, the SN861 leverages Fadu’s FC5161 controller, which complies with NVMe 2.0 standards. This controller stands out with its impressive specs, featuring 16 NAND channels and an ONFi 5.0 interface capable of speeds up to 2400 MT/s. It also boasts enterprise-level features including OCP Cloud Spec 2.0, SR-IOV support, a flexible data placement strategy, and robust security measures, making it distinct from other commercially available controllers.

When it comes to performance, the Ultrastar DC SN861 delivers incredible speeds—offering up to 13.7 GB/s for sequential reads and up to 7.5 GB/s for writes. In terms of handling random data, it achieves up to 3.3 million IOPS for 4K reads and up to 0.8 million IOPS for writes, catering to the demands of modern enterprise and cloud environments. This drive comes in sizes ranging from 1.6 TB to 7.68 TB, with options of one or three drive writes per day over a five-year period, and is available in both U.2 and E1.S form factors.

Despite their shared foundation, the two form factors of the SN861 cater to different needs. The E1.S form factor focuses on the cloud environment, supporting features like FDP and enhancing performance metrics suitable for such applications. Meanwhile, the U.2 model is tailored for high-demand enterprise tasks and cutting-edge applications like AI.

Undoubtedly, the Ultrastar DC SN861 is packed with impressive capabilities and another remarkable trait is its efficient power usage, drawing just 5W when idle. This power efficiency is noteworthy, especially in hyperscale environments where thousands of drives are deployed, and a mere watt of savings can significantly impact total operational costs.

Currently, Western Digital’s Ultrastar DC SN861 is available to select clients, including industry giants like Meta, as well as other interested companies. Pricing information remains under wraps, as it is expected to vary based on order volumes.

For more, you could refer to insights from Fadu and Storage Review.