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Kimi / MoE

Kimi-K2.5

The multimodal starting point for the K2 series

Model releaseSources checked 2026-09-13

K2.5 is worth understanding as the early multimodal K2 baseline, even if you deploy a newer checkpoint. It makes the distinction between active compute, expert storage and vision processing concrete.

1,000Breported total parameters
32Bactive parameters per token
262,144configured token positions

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

Evaluate it for

Reproducing K2-era evaluations and understanding large multimodal MoE deployment.

Choose another path when

A fresh deployment where a newer K2 variant has already demonstrated better task outcomes at the same operating cost.

Release context

Why this release matters

The released artifact combines quantized experts with other components at different precision. Its 32B active count never meant that the whole model could occupy a 32B-sized memory budget.

Release evidence · 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

4 × GB200 GPUs

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

NVFP4 variant

vLLM + Blackwell kernels

Four Blackwell GPUs are documented; this is a re-quantized artifact, not the original checkpoint at a new flag.

Checkpoint and source

See linked K2.5 NVFP4 recipe

Checked 2026-09-13. Read the documented setup →

Hardware specifications and interconnect →

595.15 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

Most experts are stored. Only a few execute.

Token representationinput to one MoE blockRouterselects experts for this tokenSelected expertsexecute and return outputsOther expertsstored, inactive for this token

Compute follows selected experts.

Weight memory follows the full expert store.

Schematic of one routed feed-forward block. The router chooses a subset for this token; all experts still need a storage location. The number of illustrated experts is not the checkpoint’s expert count.

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-K2.5
Text model typekimi_k2
Layers61
Hidden width7,168
Attention / KV heads64 / 64
Head dimensionNot verified
Routed / selected experts384 / 8
Configured positions262,144
Documented extensionNot recorded for this checkpoint
Inputs → outputtext, image, video → text
License metadatamodified-mit · 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?

K2.6 is the direct successor; GLM-5 offers a text-focused sparse-attention comparison.

20 Apr 2026

Kimi-K2.6

Keep the hardware fixed; compare the completed work

1,000B reported total · text + image + video

12 Feb 2026

GLM-5

A large sparse-attention foundation for the GLM line

744B reported total · text

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

Budget the vision encoder separately and explain why sparse expert routing does not remove inactive weights.

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-K2.5: release, architecture and deployment”, checked 2026-09-13. Preserve this date and the exact checkpoint when citing.

Model and research notes as JSON · Moonshot AI profile