Hot Chips 2026: Samsung reveals a three-phase HBM roadmap that puts logic and compute inside memory — zHBM ultimately stacks DRAM directly on top of the processor

Samsung has unveiled a three-phase roadmap to progressively transform high-bandwidth memory (HBM) into an integrated memory-and-compute system, culminating in the company's zHBM architecture, which places the processor directly beneath the DRAM stack and eliminates the conventional 2.5D interposer link between the two. Detailing the roadmap at Hot Chips 2026, Samsung's Sangwook Han, of the company's DRAM design team, identified the base die as the key enabler of the evolution, which began with the company’s decision to manufacture the HBM base die on an advanced logic process.In conventional HBM, the base die (B-die) was fabricated on the same DRAM process node as the core dies (C-dies) in the stack above. Starting with HBM4, Samsung moved the base die to a 4nm logic process, primarily to reduce power draw and minimize die area. Additionally, it gave Samsung a much more capable piece of silicon.