SK Hynix Teams Up with SanDisk to Promote HBF Standard, AI Storage Transactions Welcome New Catalyst

August 4th - According to a PDF press release from SK Hynix's Newsroom on August 4th, SK Hynix and SanDisk released the first standard specification of HBF (High Bandwidth Flash) through OCP and showcased related AI memory solutions at FMS 2026 held in Santa Clara, California, USA.

HBF is positioned as a new storage layer between HBM and SSD. According to SK Hynix, HBF aims to provide larger capacity using NAND technology while achieving high-speed data transfer capabilities close to HBM to address the "memory wall" brought by AI inference expansion. The first version of the standard covers up to 512GB capacity, based on 8-layer and 16-layer NAND die stacking, with bandwidth divided into three levels, ranging from approximately 0.4TB/s to 3.0TB/s. In terms of interconnect, UCIe is used, which means it can be more flexibly integrated with processors such as GPUs and CPUs in the future.

This release comes at a time of significant volatility in the memory stock market. In July, AI storage transactions sharply cooled down, with SanDisk and Micron both plummeting by about 47% and 29% respectively, while the Roundhill Memory ETF fell by approximately 32% during the month. However, as August began, chip stock sentiment started to recover, with the PHLX Semiconductor Index rising by over 1% on Monday, NVIDIA seeing a nearly 3% increase, and Micron and SanDisk also experiencing rebounds. The market is torn between concerns of overheated valuations in the previous period and the ongoing search for evidence that AI infrastructure demand has not cooled down.

From this perspective, the significance of the HBF standard goes beyond just a new product release. It points to the next stage of AI infrastructure: compute clusters no longer only compete based on GPU quantity, but memory bandwidth, capacity, power consumption, and data movement efficiency will also become systemic performance bottlenecks. SK Hynix and SanDisk's choice to disclose the standard through OCP is also an effort to push HBF as an open ecosystem rather than a single-vendor specification. Google and Tenstorrent have already joined the HBF Alliance, and SK Hynix will also discuss with Google DeepMind and SanDisk during FMS on how to break through the memory bottleneck using HBF.

The press release also revealed that SK Hynix publicly demonstrated the 10th-generation 375-layer 4D NAND wafer and products for the first time, claiming a 2.5x performance improvement per watt over the previous generation. They plan to mass-produce high-performance, high-capacity eSSDs based on this technology early next year. This is new foundational material for recent enterprise SSD pricing by traders, NAND price increases, and AI data center storage demand.