HBM4
The next high-bandwidth-memory generation with wider interfaces and a logic base die, targeting late-2020s accelerators.
Current numbers
~288 GBHBM4 per Rubin GPU at ~22 TB/s; trajectory H100 80 GB → H200 141 GB → B200 180 GB → B300 288 GB → Rubin Ultra 1 TB
~288 GBHBM4 capacity per Rubin-class package at ~2.75 TB/s/stack (~22 TB/s per package) — the memory the package area enables
~$350–580 → ~$560–700 per stackindicative HBM3E → HBM4 per-stack price; 8-12 stacks per accelerator