Overview
- SK hynix and SanDisk publicly released the HBF specification on Tuesday, Aug. 4, 2026, and disclosed it through the Open Compute Project to make the format available as an open industry standard.
- The specification defines HBF packages up to 512 GB using 8-high and 16-high NAND die stacks and sets three bandwidth grades that range from about 0.4 TB/s to 3.0 TB/s.
- HBF adopts the Universal Chiplet Interconnect Express (UCIe) interface so HBF devices can connect to GPUs and CPUs with standard chiplet links rather than a proprietary connector.
- Google and AI chipmaker Tenstorrent are founding members of the HBF consortium that began in February, with the group planning to add partners to build an ecosystem and technical support for the new tier.
- SK hynix unveiled its V10 375-layer 4D NAND at FMS 2026 and said it plans mass production of enterprise SSDs using that NAND early next year, but the timing is company guidance and subject to development and market risks.