Specifications

HBM4E vs HBM4: what the E adds

HBM4 moved the interface to 2048 bits and put a logic base die under the stack; HBM4E keeps that architecture and raises the pin rate. SK hynix quotes up to 16 Gbps per pin on a 2048-bit interface, which lands at roughly 4.0 TB/s per stack against about 2.0 TB/s for standard-rate HBM4 — the same 48 GB capacity, doubled bandwidth. Samsung quotes a comparable 3.6 TB/s figure for its HBM4E, so the two vendors are within a generation of each other on paper.

For accelerator designers the practical consequence is that memory bandwidth stops being the binding constraint on large-model inference and the compute-memory balance shifts. It is also why the silicon base die matters: HBM4E puts a logic substrate under the DRAM stack that can host memory controllers and PHY, so customers can embed functions directly in the memory stack rather than only in the accelerator die. Volume availability tracks the HBM4 ramp programme rather than being separately scheduled.

SK hynix products are supplied by QS Compute with B2B pricing, global shipping and short sample lead times for AI data center, edge deployment and industrial integration projects.