DeepSeek V4 Flash MLX Q2 Mixed

This is an MLX conversion of deepseek-ai/DeepSeek-V4-Flash.

Source

• Base model: deepseek-ai/DeepSeek-V4-Flash
• Source revision: 6e763230a9d263eca2023f1d4a5ce1bfe126cf48
• Architecture: DeepseekV4ForCausalLM
• Model type: deepseek_v4

Conversion Recipe

• Tooling branch: Thump604/mlx-lm, branch deepseek-v4-support-fixes
• Minimum tooling commit for generation: 9c990f4
• Output path during conversion: /Volumes/Lexar/mlx_models/DeepSeek-V4-Flash-MLX-Q2-mixed-gs128-affine
• Quantization recipe: mixed_2_6
• Quantization mode: affine
• Group size: 128
• Effective bits per weight reported by MLX: 2.992
• Shards: 23
• Indexed MLX tensor size: 106,355,393,628 bytes

The mixed recipe uses 2-bit affine quantization for lower-risk routed expert paths and 6-bit affine quantization for sensitive paths including embeddings, LM head, attention projections, compressed-attention/indexer components, shared experts, and selected down projections.

Validation

• Conversion completed successfully.
• Lazy MLX load completed successfully on a 128GB Mac Studio.
• Raw prompt generation smoke completed successfully with --max-tokens 2 --max-kv-size 1024.
• Observed smoke numbers: 54.59s real time, 74.5GB max RSS, 106.94GB peak footprint, zero swaps.

This artifact is a low-bit local fallback. It is not quality-qualified for production writing or coding lanes. Treat quality, long-context behavior, and sparse compressed-attention parity as open until evaluated with a real task suite.

Notes

DeepSeek V4 support in MLX is still under active development. This artifact was produced with local DeepSeek V4 support fixes, including FP4/FP8 checkpoint handling, F8_E8M0 scale metadata reinterpretation as raw uint8 exponent bytes before sanitizer decode, attention sink dtype handling, and quantized grouped output projection support.