Western Digital Teases 128 TB Enterprise SSD: BiCS8 3D QLC for AI Workloads

A week after Western Digital confirmed that it had begun sampling of its 64 TB SSDs for datacenters, the company has teased its next-generation product, a 128 TB solid-state drive at FMS 2024.

For now, all we know about Western Digital's 128 TB SSD is that it uses the company's BiCS8 QLC NAND memory and is designed primarily for 'fast AI data lakes and capacity-intensive performance applications,' as Western Digital does not seem to be disclosing too much information about its upcoming product. The sample on the show floor indicates the usage of a U.2/U.3 form-factor suitable for GPU servers.

BiCS8 NAND has 218 layers and uses a hybrid bonding scheme that is being tagged as CMOS directly bonded to Array (CBA). It must be noted that this technique is an evolutionary successor to Micron's CMOS-under-Array (CuA) and SK hynix's Periphery-under-Cell (4D PUC) technologies. BiCS8 NAND can interface to the controller at rates of up to 3600 MT/s, making it suitable for Gen 4+ drives.

The technology demonstration on the show floor had the drive's firmware optimized for AI checkpointing - a workload that involves sequential writes, but also requires the drive to support a minimum QoS for simultaneous read operations.

Western Digital is not the only company to talk about high-performance 128 TB SSDs. Samsung recently said that it has technology to build 120 TB-class drives, and Solidigm was also demonstrating a proof-of-concept 122 TB QLC SSD at FMS 2024. AI workloads have triggered an insatiable need for dense and power-efficient storage in the data center. This has served as an impetus for enterprise SSD vendors to continue pushing the envelop on the per-drive capacity front.