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MiniMax M3 / Lab profile

MiniMax

Study how sparse attention changes what the GPU reads.

M3 is the MiniMax checkpoint covered in this edition. Its native multimodal training, million-position configuration and sparse-attention design make it a useful model for reasoning about long agent tasks. The June announcement and later open-weight availability are separate events.

Architecture trajectory

What connects these models?

MiniMax Sparse Attention uses a lightweight indexer to select relevant KV blocks. The key distinction for a learner is between retained context and the subset read for a query. Sparse reads can reduce attention bandwidth without shrinking every part of the stored cache by the same factor.

Store the history. Read the selected parts.

Retained KV historyall state required by the modelIndex / selectionfind relevant blocksSelected KV blocksa subset of the retained historyAttention outputcomputed from selected reads

Fewer bytes read can reduce bandwidth pressure.

That does not prove an equal reduction in stored bytes.

Schematic of block-sparse attention. The indexer selects relevant blocks; attention reads those blocks from retained state. Index sharing can reuse selection work across layers. Read traffic, index work and allocated KV capacity are separate quantities.

Newest first / grouped sequence, not a time scale

The MiniMax M3 timeline

  1. MiniMax-M3

    Sparse reads do not automatically mean a small cache

    The June model combines 428B total parameters, roughly 23B active and native multimodal training. MiniMax Sparse Attention adds a lightweight indexer to select blocks; the full retained state still needs its own capacity budget.

    The announcement promised weights within ten days. We verified the current open checkpoint, not a precise first-publication day.

    Release evidence ↗

Which other labs should you compare?

GLM-5.2 is useful for comparing index sharing with block selection. Kimi K2.6 supplies a contemporary multimodal MoE alternative. Keep prompt lengths and the agent harness fixed before attributing a difference to the attention mechanism.

GLM

Z.ai

Track the attention changes separately from the post-training gains.

Kimi

Moonshot AI

Follow the jump from a coding update to a new attention stack.

Interview preparation

What you should be able to explain

Draw a large retained cache, a small block index and the selected reads. Explain why reducing read traffic and reducing allocated memory are distinct achievements.

Study the underlying systems → · Get the illustrated report →

Sources and scope

Checked 13 September 2026. Assessments and comparison candidates are our interpretation of the cited designs, not measured cross-lab rankings. Each timeline entry links to its release evidence; model pages preserve pinned card and configuration sources.