What happened
Micron said it began volume shipments of its 36 GB 12-high HBM4 in the first quarter of 2026 for NVIDIA Vera Rubin. The company also outlined an HBM4E roadmap for later AI platforms.
Why it matters
Accelerator supply depends on high-bandwidth memory and advanced packaging as well as GPU wafers. A memory ramp can therefore become a gating item for complete rack shipments.
What to watch next
- Shipment scale, customer qualification, yields, and the HBM4E production schedule.