Sandisk and SK Hynix are developing high-bandwidth flash (HBF), a NAND-based memory technology intended to give AI accelerators far more local capacity than conventional high-bandwidth memory (HBM). It could allow GPUs to combine fast HBM with terabytes of lower-cost, high-capacity flash memory, potentially reducing the need to spread large AI models across several processors.

Sandisk says first-generation HBF could deliver read speeds of up to 1.6 TB/s and 512 GB per 16-layer module, more than 14 times the capacity of current HBM4 stacks; later versions are intended to exceed 2 TB/s and eventually reach 3.2 TB/s. However, NAND has microsecond-scale latency and limited write endurance compared with DRAM, so HBF is not expected to replace HBM outright. Instead, it would support read-heavy AI inference work, while HBM handles write-intensive operations such as generating key-value caches.