High-Bandwidth Memory (HBM)
Stacked DRAM wired straight to the GPU — the scarcest commodity in AI.
You're looking at a technology record: a building block of AI hardware — what it does, who makes it, and which chips and systems use it.
HBM stacks DRAM dies vertically, connects them with thousands of through-silicon vias, and mounts the stack millimeters from the processor on a silicon interposer. The result is terabytes per second of bandwidth that ordinary DIMMs cannot approach — and because model inference is mostly memory-bound, HBM capacity and bandwidth, not FLOPS, usually decide real AI performance. Only SK hynix, Samsung and Micron make it, and supply has been sold out roughly a year ahead throughout the boom.
Specifications & key facts
Each figure is labeled by basis: vendor spec, vendor claim, reported, estimate, or official. "Not publicly disclosed" means exactly that — we never invent values.
Overview
How this connects to the rest of the stack
This record's links at a glance — click a group to jump to it.
Sources
Record reviewed as of 2026-01-15 — see Methodology.