DRAM, that’s fast: SK hynix reaches for HBM3E sky

South Korean memory fabber SK hynix is sampling an HBM3E chip, a month after Micron’s gen 2 HBM3 chip was unveiled.

HBM3E is High Bandwidth Memory gen 3 Extended and follows the HBM3 standard which was introduced in January 2022. Such memory is built from stacks of DIMM chips placed above a logic die, which is attached to an interposer that connects them to a GPU or CPU. Alternatively the memory chips can be directly stacked on the GPU. Either way the DRAM-to-GPU/CPU bandwidth is higher than the traditional X86 architecture of DRAM connected by sockets to the processor. Industry body JEDEC specifies HBM standards and its HBM3 standard was issued in January. Now vendors, incentivized by the AI and ML boom, are rushing to make it out of date.

SK hynix is facing depressed revenues because of memory and NAND over-supply in a low-demand market, though the memory market is starting to show some signs of recovery. Sungsoo Ryu, Head of DRAM Product Planning at SK hynix, said: “By increasing the supply share of the high-value HBM products, SK hynix will also seek a fast business turnaround.”

HBM generations table.

The company characterizes itself as one of the the world’s only “mass producers” of HBM3 product and plans to volume produce HBM3E from the first half of next year. SK hynix talked up its production of memory for the AI market, currently being significantly enlarged by demand for ChatGPT-type Large Language Models (LLMs). SK believes that LLM processing is memory limited and aims to rectify that.

Details of the SK hynix product are few, with the company only saying it can process data up to 1.15 terabytes(TB) a second, which is equivalent to processing more than 230 full-HD movies of 5GB-size each in a second. Micron announced a more than 1.2TBps HBM3 gen 2 product last month, suggesting that SK hynix has work to do.

Micron’s HBM3 gen 2 product has 24GB capacity using an 8-high stack, with a 36GB capacity 12-high stack version coming. SK hynix announced a 12-stack HBM3 product in April, with 24GB of capacity.

We suspect that SK hynix’s HBM3E product may be developed from this 24GB capacity, 12-stack offering and could achieve 36GB.

SK hynix says the HMB3E product is backwards-compatible with HBM3; just drop it in to an existing design and make the system go faster.