High Bandwidth Memory (HBM) is essential for AI training. SK Hynix and Samsung control over 95% of global HBM production, with chronic supply shortages.
High‑bandwidth memory (HBM) is the critical complement to frontier accelerators. Supply is concentrated and tightly coupled to packaging yields and substrate availability.
HBM capacity, binning, and reliability determine effective accelerator throughput. When HBM is short, compute is short. The constraint is as much packaging and qualification as it is DRAM wafer capacity.
A small set of firms controls most HBM output. This amplifies shocks, makes long‑term contracts valuable, and turns ramp decisions into strategic levers.
HBM availability depends on advanced packaging throughput and substrates. Memory cannot be analyzed in isolation from the packaging layer.