# Naive-N0.5-Flash (309B)

> MiMo-V2.5-derived sparse MoE that replaces its global attention layers with GQA-based DeepSeek Sparse Attention for a native 1M-token context.

| Property | Value |
| --- | --- |
| Lab | NaiveAI (China) |
| Released | 2026-09-27 |
| Decoder type | Sparse MoE |
| Family | Sparse MoE |
| Scale | 309B total, 15.5B active (5.0% active) |
| Context window | 1,048,576 tokens |
| Attention | GQA with sliding-window attention and DeepSeek Sparse Attention |
| Layer mix | 39 sliding-window + 9 GQA/DSA |
| KV cache / token (bf16) | 219.75 KiB (High) |
| License | MIT License |

**Key detail:** Pairs a 128-token local window with top-2,048 DSA selection, four DSA KV heads, and a 16-head indexer. Uses 256 routed experts with top-8 routing and no full-attention layers.

## Architecture concepts

- [Grouped-Query Attention (GQA)](https://llm-atlas-7or.pages.dev/concepts/gqa.md): Several query heads share one key/value head, shrinking the KV cache with little quality loss.
- [Sliding Window Attention (SWA)](https://llm-atlas-7or.pages.dev/concepts/swa.md): Some layers only attend to a local window of recent tokens instead of the whole context.
- [DeepSeek Sparse Attention (DSA)](https://llm-atlas-7or.pages.dev/concepts/deepseek-sparse-attention.md): A lightweight indexer scores past tokens and each query attends only to its top-k picks.
- [Mixture of Experts (MoE)](https://llm-atlas-7or.pages.dev/concepts/moe.md): Many feed-forward experts, but a router sends each token to only a few of them.

## Links

- Architecture diagram: https://sebastianraschka.com/llm-architecture-gallery/images/architectures/naive-n0-5-flash-309b.webp
- config.json: https://huggingface.co/NaiveAI/Naive-N0.5-Flash/blob/main/config.json
- License: https://huggingface.co/NaiveAI/Naive-N0.5-Flash/blob/main/LICENSE
- Tech report: https://naive.ai/en/research/
- Source card (source of truth): https://sebastianraschka.com/llm-architecture-gallery/#card-naive-n0-5-flash-309b
- Web page: https://llm-atlas-7or.pages.dev/models/naive-n0-5-flash-309b/
- JSON: https://llm-atlas-7or.pages.dev/api/models/naive-n0-5-flash-309b.json

_Data from Sebastian Raschka's LLM Architecture Gallery (https://sebastianraschka.com/llm-architecture-gallery/). Synced 2026-11-04._