- SanDisk reveals high bandwidth flash (Hbf), a NAND-based alternative to HBM
- HBF matches HBM -band width that offers 8–16x capacity at a lower price
- SanDisk plans to set up a technical advisory board experts
It certainly seems that split from Western Digital has lit a fire under Sandisk. On its recent investor’s day, the flash memory specialist sees the wrapping of super large SSDs, with the promise of even bigger coming, and revealed a new, cheaper drama alternative called 3D Memory Matrix.
At the same arrangement, SanDisk also revealed his High Bandwidth Flash (HBF) concept aimed at HBM by increasing it with NAND -FLASH to accommodate AI -Inferens work loads. Sandisk’s central target with HBF seems to be matching HBM ribbon width while delivering 8-16 times the capacity at a similar price.
According to a slide that SanDisk Shared, HBF combines BICS technology with CBA WAFER binding, enabling effective stacking of high density. The company has developed a proprietary stacking technology that reportedly delivers Ultra-Low Die Warpage, which makes it possible to achieve 16-die stacking without major structural problems.
Scaling up to 4tb
The architecture of HBF has been developed in the past year in which SanDisk incorporates input from “Major AI players” (it does not name names, unfortunately).
The diagram in the slide shows an HBF stack consisting of several HBF core connected via TSV (through-silicon via) and microbuds, interface with a logic die and phy, which then connects to a GPU, CPU, TPU or SOC dies. The whole stack sits on an interposer on top of a package substrate, similar to the packaging design used in HBM.
HBF is not a straight drop-in replacement for HBM, but it shares the same electrical interface, so it only requires minor protocol adjustments, according to SanDisk.
In another slide, a GPU is compared with HBM, which delivers 192 GB of total memory, with an alternative version that combines HBF and HBM, which increases the memory capacity to 3TB. A fully optimized setup with only HBF (which you can see at the top of the page) can scale up to an impressive 4TB.
Sandisk’s HBF Roadmap (below) shows how the company sees the technology progressing across several generations, focusing on capacity, reading bandwidth and energy efficiency. In the first generation, HBF establishes a baseline for these measurements. At the second generation, capacity is expected to rise by 1.5x, while reading bandwidth sees an improvement of 1.45x and energy efficiency drops slightly to 0.8x. At the third generation (there is no indication of when SanDisk expects to arrive at this time), HBF is expected to double the capacity and read bandwidth compared to its original version, where energy efficiency drops further to 0.64x.
HBF is likely to receive some push back from rivals like Samsung and SK Hynix, which is heavily invested in the HBM market of $ 100 billion. SanDisk is painfully aware of this and is looking to establish an open standard ecosystem and also a technical advisory board consisting of industrial experts and key partners.
