Why only 6bit? On this 1B model, protection floors dominate storage, so both the ~4.8 and ~6.0 BPW budgets land at **7.38 BPW** with identical weights. There is no smaller AXQ-4bit sibling — use this pack only.

AX-MiniCPM5-1B-MLX-AXQ-6bit

An AXQuant (AXQ) mixed-precision MLX checkpoint for Apple Silicon, converted directly from the BF16 source model. The language path is quantized under AXQuant protection floors (embeddings, norms, and other protected tensors remain higher precision).

Development evidence — not a certified AXQuant release. This package has conversion and artifact-integrity records, but it does not publish measured quality, long-context, kernel-speed, or MTP-speed evidence. Do not interpret the AXQ product label as a benchmark claim.

Stable-name v2. main serves the audited v2 artifact for backward compatibility. The same revision is tagged v2; the replaced artifact remains recoverable at legacy-pre-v2.

Model details

Property	Value
Base model	openbmb/MiniCPM5-1B
Source revision	4e9de7a0778dc1c362e983e6858f0e77542cbdca
Product family	minicpm5
Source architecture	LlamaForCausalLM (dense); text path optimized
Main-model parameters	1.08B logical parameters
Quantizer	AXQuant 1.2.0
Hub budget class	6bit
Artifact edition	v2
AXQuant base precision class	7p4bpw
Planned storage-adjusted BPW	7.3800
Measured main-model BPW	7.3804
Measured total BPW	7.3804
Safetensors weight size	1.00 GB
Approximate complete download	1.01 GB
Configured maximum context	131,072 tokens; practical limits depend on unified memory
MLX-LM compatibility	Standard text inference, compatibility level B
AX Engine native execution	Not established; no validated native manifest is included
MTP present	False
Vision sidecar present	False

This repository contains MLX Safetensors. It does not contain PyTorch or GGUF weights.

Why there is no AXQ-4bit pack

MiniCPM5-1B is small, so protected high-precision tensors (embeddings, norms, and other floors) are a large share of the model. AXQuant therefore raises both the low-memory (~4.8 BPW) and 6 BPW budgets to the same effective target of about 7.38 BPW — already above a uniform 6-bit budget.

The former …-AXQ-4bit sibling was byte-identical to this pack (~1.0 GB). A separate 4bit name would incorrectly suggest lower memory use. AutomatosX keeps only this repository.

Measured main-model BPW	~7.38
Package size	~1.0 GB
Why not 4bit	Floor-collapsed; identical to this pack

Choosing an AXQ pack

AXQ 4bit / 6bit names are storage-budget product classes, not a promise that every tensor uses that width. On this base there is no distinct 4bit Hub pack — see Why there is no AXQ-4bit pack above.

Sibling	Intended trade-off
(none published)	This 6bit pack is the only public AXQ checkpoint for this base.

See the AutomatosX MLX model catalog for related MLX and OptiQ alternatives.

Download

python -m pip install -U huggingface_hub
hf download AutomatosX/AX-MiniCPM5-1B-MLX-AXQ-6bit --local-dir ./AX-MiniCPM5-1B-MLX-AXQ-6bit

Allow at least 1.01 GB of free disk space. Pin the resulting Hub commit in reproducible deployments rather than relying indefinitely on main.

Run with MLX-LM

python -m pip install -U mlx-lm
mlx_lm.generate \
  --model AutomatosX/AX-MiniCPM5-1B-MLX-AXQ-6bit \
  --prompt "Explain mixed-precision quantization in three sentences." \
  --max-tokens 128 \
  --temp 0.0

MLX-LM compatibility covers standard text/backbone inference. It may ignore AXQuant runtime metadata and optional sidecars (vision.safetensors, mtp.safetensors); this command therefore does not establish MTP acceleration or vision-language quality. The artifact records MLX 0.32.0 and MLX-LM 0.31.3 from conversion.

AX Engine status

This package does not include a validated native model-manifest.json, so AX Engine execution is not established by this release. The AX Engine fields in axquant_runtime.json describe the intended compatibility contract, not observed runtime evidence. Use the MLX-LM path above for standard text/backbone inference. The artifact records AX Engine version not recorded, but version discovery alone is not a runtime check.

Quantization layout

Main-weight precision	Parameters	Share
4bit	679.48M	62.88%
8bit	200.54M	18.56%
bf16	200.62M	18.56%

• Quantization methods: affine, bf16.
• Group sizes used by quantized assignments: 32, 64.
• MTP sidecar: not included.
• Vision sidecar: not included.
• Optimization scope: text-path.
• Support tier: convertible.

BF16 sidecars, when present, are included in total download size. Their presence does not by itself establish MTP acceleration or vision-language quality.

Evidence and validation status

Check	Status
Planning evidence	architecture_prior
Calibration	none; the allocation is based on architecture priors
Quantizer execution	169/169 recorded module conversions succeeded; 0 fallbacks
AX Engine native manifest	not included
Quality versus BF16 or uniform baselines	Not published; no quality-retention claim
MTP acceptance and speed	not measured; no MTP speedup claim
AX Engine kernel evidence	unmeasured
Vision-language quality	Not applicable (no vision sidecar in this package)
Long-context quality	131,072-token capacity is config metadata, not a validated claim
Release certification	Not certified; formal AXQuant M0-M8 gates are not closed

Intended use and limitations

• Intended for local development and evaluation on Apple Silicon with MLX-compatible runtimes.

• No minimum unified-memory figure is claimed; loadability depends on model size, context length, KV-cache policy, runtime buffers, and other processes using unified memory.

• Architecture-prior allocation is not measured sensitivity. It must not be presented as measured model quality.

• The configured context window can require substantially more memory as the KV cache grows.

• AX Engine execution is not established because this package has no validated native manifest.

• Upstream capabilities, limitations, biases, and responsible-use guidance still apply.

Provenance and audit files

• axquant_manifest.json: package identity, byte accounting, runtime contract, software versions, and file checksums.
• axquant_plan.json: per-tensor precision decisions and planning evidence.
• axquant_quantizer_execution.json: conversion coverage and fallback records.
• axquant_runtime.json: declared AX Engine and MLX-LM compatibility metadata; runtime checks remain separate evidence.

All published provenance uses repository-relative paths. Local source paths are stripped before publication. The checkpoint was converted from BF16 rather than re-quantized from an OptiQ artifact. Parallel OptiQ repositories use a different quantizer and should not be assumed to have identical BPW or quality.

License

The checkpoint follows the upstream model license where applicable (often Apache License 2.0). See the openbmb/MiniCPM5-1B model card for license terms, model limitations, and responsible-use guidance.