hbf

P Equity Research and SemiAnalysis researcher Nick Doyle and others discussed high bandwidth flash (HBF) in X Space. Nick stated that it is still too early to determine how much the cost premium of HBF relative to HBM can shrink; existing data mostly comes from vendor claims, such as Sandisk stating that the cost per bit is about one-eighth that of HBM. Yields, testing, and other factors will improve with scale, but structural costs such as TSV, stacking, and pSLC mode will always exist, and durability is a key unknown; if wear exceeds expectations, costs will rise.The application scenarios for HBF are narrow, targeting only AI inference, especially low batch and long context MoE models, and it is not a substitute for HBM. The actual bandwidth target is about 1.6 TB/s, which is at the HBM3E level, suitable for sequential reads to load model weights, more aligned with the capacity needs of a small number of GPUs in local or private enterprises, rather than ultra-large-scale bandwidth scenarios. Heat dissipation reliability has not yet been resolved; flash memory will degrade faster at high temperatures next to GPUs, and mitigation measures such as UCIe separation and daily refresh have yet to be validated.In terms of manufacturing, Sandisk/Kioxia has experience with 3D NAND, and SK Hynix complements HBM-style stacking capabilities, but mass production is still to be confirmed. Overall, storage is shifting towards a specialized layered market, with NAND shortages expected to continue until 2028, and HBF may further impact supply and demand.

SK Hynix announced at the FMS 2026 conference the joint release of the first High Bandwidth Flash (HBF) standard specification with Sandisk, just about 6 months after the establishment of their alliance in February this year. The standard is publicly available through OCP and covers key specifications such as capacity (up to 512GB), bandwidth (divided into three levels, with a maximum of approximately 3.0TB/s), and the use of the UCIe interconnect interface. Google and Tenstorrent have confirmed their participation in the HBF alliance.The HBF technology is positioned as a new storage tier between HBM and SSD, combining HBM-level high-speed transmission with NAND's large capacity expansion capabilities. SK Hynix publicly showcased the 10th generation (V10) 375-layer 4D NAND wafers and products for the first time during the exhibition, achieving a 2.5 times improvement in energy efficiency compared to the previous generation, with mass production expected early next year. During the conference presentation, SK Hynix executives proposed using a "Tiered Memory" architecture to address the data processing challenges of the AI inference era.