SK hynix shares rebounded 1.98% overnight to $145.55, recovering from a 0.70% decline that had brought the stock to $142.72 at Tuesday's close. The recovery came after new details emerged regarding the company's High Bandwidth Flash (HBF) partnership with Sandisk, including the introduction of an open industry standard designed to improve storage performance across modern data centers.

SK hynix and Sandisk Establish High Bandwidth Flash Standard

At FMS 2026 in Santa Clara, California, SK hynix and Sandisk unveiled the first standard specifications for High Bandwidth Flash technology. The initiative addresses escalating data demands driven by larger inference workloads and increasingly complex computing systems.

High Bandwidth Flash occupies a position between high-bandwidth memory and solid-state drives, combining accelerated data movement with greater storage capacity through NAND technology. The architecture is designed to support systems that require both high speed and expanded capacity. As AI models grow larger and inference workloads scale, the bandwidth gap between fast but limited-capacity HBM and slower but higher-capacity SSDs has become a recognized bottleneck — the category HBF targets.

The two companies began formal standardization efforts in August 2025 and established a consortium in February 2026. The newly published specifications support capacities of up to 512GB through eight-high and sixteen-high NAND stacks. They also define three bandwidth grades, ranging from approximately 0.4TB per second to 3.0TB per second.

Open Standard Broadens Processor Compatibility

The specification employs Universal Chiplet Interconnect Express to connect High Bandwidth Flash with processors. This interface enables integration with multiple processor types, including graphics processing units and central processing units, allowing system designers to incorporate the technology across diverse hardware platforms.

The standard encompasses electrical characteristics, connection methods, reliability requirements, packaging rules, and software input-output guidance. SK hynix and Sandisk published the specification through the Open Compute Project, making the framework available for broader industry adoption rather than restricting it to a single vendor. Publishing through OCP also positions HBF for potential adoption within hyperscaler data center designs, where OCP-defined hardware specifications are widely used.

Google and Tenstorrent are already participating in the High Bandwidth Flash consortium. The group intends to recruit additional members and further develop technical maturity. Wider participation is expected to help suppliers align their products around shared performance and compatibility benchmarks.

SK hynix Showcases Next-Generation NAND Products

During FMS 2026, SK hynix also presented its tenth-generation 375-layer 4D NAND wafer. The product, still under development, delivers improved efficiency over the previous generation, with performance per watt enhanced by 2.5 times.

The new NAND targets data centers that demand higher performance and reduced power consumption. SK hynix plans to commence mass production of related enterprise solid-state drives early next year, a move that could reinforce its position in high-capacity storage for advanced computing systems.

The company additionally showcased products designed for mobile devices, personal computers, vehicles, and robotics. Executives outlined a tiered memory architecture that combines multiple memory technologies within a single system. SK hynix is leveraging the event to promote broader adoption of High Bandwidth Flash across storage markets, building on its established leadership in HBM to address a broader segment of the AI memory and storage stack.