Overview
- SK hynix and SanDisk released the High Bandwidth Flash (HBF) specification through the Open Compute Project at FMS 2026, defining packages up to 512 GB, three bandwidth grades from about 0.4 TB/s to 3.0 TB/s, and use of the UCIe interface to connect HBF to CPUs and GPUs.
- The partners position HBF as a new tier between HBM and SSDs that trades some latency for much higher capacity near the accelerator so large AI models can be held closer to compute during inference.
- Samsung unveiled alternative paths at the same show, including a wafer‑bonded zHBM concept that stacks HBM over AI accelerators and a 400+‑layer BV‑NAND design, with the company claiming far higher density and energy efficiency for its approach.
- Industry uptake is uncertain because only Google and Tenstorrent have publicly joined the HBF consortium and rival interfaces and form factors from Samsung and others could fragment the market and lock customers to vendor‑specific designs.
- Commercial samples and revenue remain future milestones with SK hynix targeting mass production of eSSDs from its 375‑layer V10 NAND early next year and the wider question now is which architecture hyperscalers and accelerator makers will standardize on.