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Kimi / MoE

Kimi-K3.1-Pro

K3's stack with sparse attention in place of full attention

Open-weight releaseSources checked 2026-11-06

K3.1 Pro belongs on the same shortlist as K3 for long-context agent work on a dedicated cluster. The change to study is architectural: the 24 full-attention layers now use gated sparse attention with a top-2048 index, which changes what a long request reads, while the 2.8T expert store and the cluster requirement stay.

2,800Breported total parameters
104Bactive parameters per token
1,048,576configured token positions

Publisher-reported, rounded model count; not an exact tensor census. Multimodal components and packaging can change the artifact size.

Evaluate it for

Long-context coding and multimodal agent evaluations on a multi-GPU Blackwell or MI355X node.

Choose another path when

A single node smaller than eight current-generation GPUs, or a runtime without kernels for both recurrent-state and sparse attention.

Release context

Why this release matters

Moonshot keeps K3's 69 Kimi Delta Attention layers and replaces the gated latent-attention layers with gated DeepSeek-style sparse attention. Selected experts per token are 16 of 896, with two shared experts.

Announced with API access on 24 October with weights promised by 4 November; the weights repository's first commit is dated 2 November.

Release evidence · Announced 2026-10-24 · Weights 2026-11-02 · Follow the Kimi timeline →

Deployment starting points

Which hardware, how many, at what precision?

Start with an exact artifact and an engine that supports it. A configuration below is evidence of a documented path; its device count does not promise a particular throughput or concurrency.

Runtime recipe

8 × GB300 GPUs

GPUs within an NVLink system; this is not a count of whole racks.

MXFP4 routed experts, BF16 elsewhere

vLLM 0.34.0+ multi-node TP8

Default command spans two GB300 trays with TP8 across nodes; network interfaces must be set for Gloo and NCCL.

Checkpoint and source

moonshotai/Kimi-K3.1-Pro

Checked 2026-11-06. Read the documented setup →

Hardware specifications and interconnect →

Runtime recipe

8 × MI355X

288 GB per GPU

MXFP4 routed experts, BF16 elsewhere

vLLM ROCm K3.1 image

One node at TP8 with the AMD AITER profile. The recipe marks it for throughput measurement only and asks for about 6 GiB free per GPU.

Checkpoint and source

moonshotai/Kimi-K3.1-Pro

Checked 2026-11-06. Read the documented setup →

Hardware specifications and interconnect →

1,561.22 GB of tensor data in the pinned index

This is the index’s reported tensor payload, in decimal GB. It excludes file headers and runtime memory. Mixed precision, conversion and host/device placement determine how much GPU memory the loaded model needs.

Inspect the exact index metadata →
Capacity screen: would the weights fit?

This estimates inference memory for a hypothetical uniform precision. It is useful for rejecting an allocation that is too small. It does not establish a working deployment or estimate training memory.

A uniform-precision GPU count would hide this model’s component layout. Publisher-reported, rounded model count; not an exact tensor census. Multimodal components and packaging can change the artifact size. Use the documented artifact and placement path above; no GPU count is inferred here.

Architecture in practice

What the serving engine has to do

Two kinds of layers retain two kinds of state.

A token enters a layerthe layer type selects its pathRecurrent layerupdate a compact stateAttention layerread retained token historyRecurrent statemaintained for this sequenceAttention cachelayout depends on the model

Hybrid attention does not mean zero request state.

A full-attention formula cannot describe every layer.

Schematic of a hybrid attention stack, not a literal layer ordering. Recurrent layers update a compact state; attention layers retain their own history. Both kinds of state matter for prefix reuse and concurrent requests.

Mechanism schematic based on the pinned model card and configuration. It explains a design principle; it is not a full implementation graph.

Inspect the full checkpoint specifications
Inspected fields for this exact revision. KV heads alone do not describe latent, hybrid or shared-cache layouts.
Exact checkpointmoonshotai/Kimi-K3.1-Pro
Text model typekimi_linear
Layers93
Hidden width7,168
Attention / KV heads96 / 96
Head dimensionNot verified
Routed / selected experts896 / 16
Configured positions1,048,576
Documented extensionNot recorded for this checkpoint
Inputs → outputtext, image → text
License metadatakimi-k3.1-pro · custom terms

Open weights do not imply unrestricted use. Read the applicable license terms linked from the pinned card.

A useful comparison

What else belongs on the shortlist?

K3 isolates the attention change on the same expert store; DeepSeek V4.1 Flash-1017 is a smaller conditional-memory alternative for similar agent tasks.

27 Jul 2026

Kimi-K3

A cluster model with a new attention design

2,800B reported total · text + image + video

17 Oct 2026

DeepSeek-V4.1-Flash-1017

Same footprint, new weights: a clean post-training comparison

552B reported total · text + image

These are editorial comparison candidates. We have not run a matched quality or serving benchmark, so this is not a ranking.

Prepare to explain it

The interview lesson

Compare K3 and K3.1 Pro layer by layer. Explain why replacing full attention with sparse attention reduces long-context read traffic without shrinking the expert store or the recurrent state.

Attention layouts · Quantization · Courses and worked examples

For a deployment evaluation, record exact weights, precision, engine, device count, interconnect, prompt/output lengths and concurrency. Report task success, errors, TTFT, TPOT and useful throughput together.

Sources and citation

Our assessment is editorial judgment based on the linked architecture and deployment evidence. Model facts are publisher-reported or attributed to runtime maintainers; no independent GPU benchmark was run.

AI Infra Interviews, “Kimi-K3.1-Pro: release, architecture and deployment”, checked 2026-11-06. Preserve this date and the exact checkpoint when citing.

Model and research notes as JSON · Moonshot AI profile