Architecture
Retrieved 2026-09-13 at pinned commit b96024342a77; parameter count from the safetensors index at the same revision.
- Architecture
- olmo2
- Layers
- 64
- Hidden size
- 5,120
- Attention heads
- 40
- KV heads
- 8
- Feed-forward width
- 27,648
- Vocabulary
- 100,352
- Context ceiling
- 4,096
- RoPE theta
- 500,000
Where the memory goes
Grouped-query attention shares each key/value head across 5 query heads, so the KV cache is 20% of what multi-head attention would need at the same context.