High Bandwidth Flash Spec Advances Sandisk, SK hynix

Sandisk Corporation and SK hynix released the first High Bandwidth Flash (HBF) technical specification through the Open Compute Project (OCP) on August 3–4, 2026, formalizing an open near-compute NAND standard for AI inference. The move has prompted analyst commentary that it broadens Sandisk’s AI-memory opportunity.

Technical Specification and Industry Collaboration

SK hynix detailed that the initial HBF specification defines two stack configurations—8-high and 16-high NAND die stacks—with capacity up to 512GB per stack. It includes three bandwidth grades scaling from about 0.4 terabytes per second (TB/s) to 3.0 TB/s. The specification adopts Universal Chiplet Interconnect Express (UCIe) as the chiplet interconnect to link HBF with CPUs and GPUs. SK hynix positioned HBF as a near-compute memory tier between high-bandwidth memory (HBM) and solid-state drives (SSD), combining HBM-class bandwidth with NAND-class capacity for AI inference workloads. The company expects full commercialization around 2030.

Sandisk’s release described the specification as a common technical framework for companies and developers building AI inference systems and accelerators. It includes system interface and electrical guidelines, an xPU-HBF host interface (xPU refers to heterogeneous processors), reliability and packaging guidance for die stacks, and a software user guide for read/write operations. Google and Tenstorrent are named consortium participants, with Sandisk and SK hynix as primary contributors to the HBF technology workstream. The companies used the OCP framework to publish the specification and foster an early-stage ecosystem around the new memory tier.

Consortium Development and Market Positioning

Sandisk and SK hynix signed a memorandum of understanding in August 2025 to collaborate on HBF standardization and ecosystem development. They co-hosted an “HBF Specification Standardization Alliance Launch Event” at Sandisk’s Milpitas headquarters on February 25, 2026, formally initiating the OCP-based workstream that produced the published specification about six months later.

No new SEC filings related to the HBF initiative or the SK hynix collaboration appeared within the past 72 hours, and Sandisk has not issued new quantitative financial guidance tied to HBF in that period. Sandisk trades on Nasdaq under ticker SNDK.

Sandisk framed the OCP publication as a deliberate open-standards strategy to position HBF as a de facto industry tier. The company aims to foster adoption, increase visibility for customers, and accelerate technological maturity and market expansion through consortium membership and collaboration.

Equity research commentary described the OCP publication as a meaningful step toward commercialization and a complement to Sandisk’s broader NAND roadmap. Analysts cited an estimated $100 billion AI memory and storage market and pointed to Sandisk’s ongoing ramp of quad-level cell (QLC) SSDs and a planned transition to BiCS10 triple-level cell (TLC) architecture as complementary drivers. These assessments represent analyst views rather than company guidance.