Sakura MiniMax-M3.1-Flash Q5_K_M GGUF

CPU requantization of the official MiniMax-M3.1-Flash hybrid NVFP4/MXFP8 checkpoint, using llama.cpp's standard mixed-type Q5_K_M policy. This is not a quantization from an unquantized BF16 checkpoint. No importance matrix or expert pruning is applied.

Runtime requirement: use the included runtime.patch with llama.cpp revision 970b51ce7c9ba5fff0726c5e9994f1c2f0e4eedc. These files use the explicit architecture identifier minimaxm31_sakura; unchanged stock runtimes reject it. M3.1 has sparse attention in all 60 layers, including its first three dense-MLP layers. The patch preserves that distinction in tensor loading, indexer KV caching and execution. A generic older M3 runtime must not silently substitute full attention in those layers.

Size comparison

The original 48 main safetensors shards total 250,116,419,880 bytes. The original DSpark file adds 2,301,867,426 bytes. The original source is already quantized: NVFP4 routed experts, MXFP8 attention paths, and retained BF16/F32 tensors.

GB = 10^9 bytes. Auxiliary-file totals include the same 1.732-GB F16 projector and 2.302-GB unchanged DSpark file in each release. Small JSON, license and runtime source files are excluded. GGUF main sizes include their metadata. The official main checkpoint includes the vision tower, which is separated into mmproj here. Q4/Q5 may be larger than the released low-precision source; increasing stored precision does not recover information lost during the source's quantization. These are file sizes, not complete RAM/VRAM requirements or speed/quality results.

Released files

Download every main GGUF shard and keep the names together; load the first shard. Each main shard is under 48 GB. SHA256SUMS records all released weight files. build-manifest.json records pinned source checksums, all target tensor types, every output tensor checksum, independent stream checksums and native Xet verification.

Source and preserved components

The standard upstream MiniMax vision converter produces the separate F16 projector. The complete original DSpark safetensors checkpoint, config and index are copied unchanged. DSpark execution is not integrated into this patched llama.cpp runtime; the original files are retained for compatible serving implementations and future integration. No speculative speedup is claimed.

Provenance and construction

• Source revision: 54e4e69dfc452b1e94a426c24a4fdeeaa8e3ad5e.
• NVFP4 source weights are decoded with per-group FP8 scales and the released global-scale convention; MXFP8 uses E4M3 weights and UE8M0 block scales. Conversion uses BF16/F32 intermediates selected by the pinned upstream converter.
• Every complete source shard is SHA256-verified before its payload is used. Tiny verified scale/norm tensors are cached in RAM to avoid repeatedly reloading unrelated large shards.
• Main expert matrices are encoded one expert at a time; embeddings are encoded in bounded row blocks. No full decoded model or full output GGUF is materialized on disk.
• Full-model tensor type assignments match the unchanged native quantization planner. Real-row decoder checks match independent native ggml/PyTorch references. The patched all-sparse runtime passes a small synthetic CPU prefill/decode check. Those checks do not establish full-model response quality; no new benchmark scores are claimed.
• All final source/producer/upload checks must pass before an atomic model commit is published. An independent finalizer can recover a completed upload from its checksum-protected provenance checkpoint.

Build the compatible runtime and run

Use build-runtime.sh alongside runtime.patch. It checks out the pinned upstream revision and applies the included patch. CPU is the default; supported GPU backends can be selected when building for your own hardware. No model weights are downloaded by the runtime build script.

bash build-runtime.sh
./minimax-runtime-build/bin/llama-server -m Sakura-MiniMax-M3.1-Flash-Q5_K_M-00001-of-00007.gguf --mmproj MiniMax-M3.1-Flash-mmproj-f16.gguf -ngl 0 -c 32768 -fa on --parallel 1 --jinja --temp 1.0 --top-p 0.95

Flash Attention and a supported stream layout are required for this M3.1 path; unsupported settings fail instead of silently using full attention. Omit --mmproj for text-only use. Set context and offloading for available memory; the source's maximum context is not a claim that it fits a particular device. Preserve the original chat template and returned reasoning content. Do not add guessed DSpark flags to this runtime.

License and attribution

Original model: MiniMax-M3.1-Flash, Copyright (c) 2026 MiniMax. This redistribution retains the MINIMAX COMMUNITY LICENSE, including its attribution, commercial-use and prohibited-use conditions. It is not Apache-2.0 or MIT model licensing. Read LICENSE before use. llama.cpp runtime code is separately covered by its upstream MIT license. Sakura identifies this quantization and distribution, not original model training.