DeepSeek-V4-Flash-0731-FP8

DeepSeek-V4-Flash-0731-FP8

This is an unofficial FP8 format conversion of DeepSeek-V4-Flash-0731, created from upstream revision 7872f01b1d1fe23eabc4c98b48bffcef5a386062. It is not an official DeepSeek release and does not claim the upstream model's published benchmark results.

The model weights and this repository are distributed under the upstream MIT License.

Format

The upstream checkpoint combines MXFP4 routed experts with MXFP8 dense, attention, shared-expert, and MTP tensors. This conversion presents a single FP8 layout for SGLang:

The float32 scales are exact casts of the source E8M0 powers of two. The checkpoint deliberately has no scale_fmt field: the tested SGLang FP8 loader reads these scales as float32 and prepares its runtime representation itself. See conversion/manifest.json for the complete format and verification record.

Conversion verification

• Converted routed-expert tensors: 35,328
• Source scale tensors cast exactly to float32: 71,046
• Routed-expert 128x128 blocks swept: 18,087,936
• Blocks with scale spread above the lossless threshold: 0
• Maximum observed dequantization error in the deterministic verification sample: 0.0

The released conversion/ scripts reproduce the conversion and verification. They require PyTorch with float8 support and safetensors; run them on a separate source and output directory.

python conversion/convert_fp4_to_fp8_f32_scales.py \
  --source /path/to/DeepSeek-V4-Flash-0731 \
  --output /path/to/DeepSeek-V4-Flash-0731-FP8

python conversion/verify_lossless_conversion.py \
  --source /path/to/DeepSeek-V4-Flash-0731 \
  --converted /path/to/DeepSeek-V4-Flash-0731-FP8 \
  --output error-metrics.json

Validated serving path

This checkpoint was validated with SGLang on AMD MI325X using four-way tensor parallelism and data parallelism. The following is the tested serving family; adapt hardware-dependent parallelism and memory values to your deployment.

python -m sglang.launch_server \
  --model-path long10024070/DeepSeek-V4-Flash-0731-FP8 \
  --served-model-name deepseek-v4-flash-fp8 \
  --host 0.0.0.0 --port 30000 \
  --trust-remote-code --tp-size 4 --dp-size 4 --enable-dp-attention \
  --quantization fp8 --mem-fraction-static 0.85 \
  --attention-backend dsa --dsa-prefill-backend aiter \
  --dsa-decode-backend aiter --dsa-topk-backend sgl-kernel \
  --kv-cache-dtype fp8_e4m3 --enable-aiter-allreduce-fusion \
  --moe-runner-backend auto --cuda-graph-max-bs-decode 8

No speculative-decoding flags were enabled for the validation runs. This repository does not claim compatibility with Transformers, vLLM, or other runtimes that have not been tested against this exact layout.

Chat formatting

Like the upstream release, this model does not include a Jinja chat template. Use the included encoding/ utilities to encode OpenAI-style messages and parse completions. They are copied unchanged from the exact upstream revision used for conversion.

Integrity

SHA256SUMS contains SHA-256 hashes for every release payload file except the checksum manifest itself. Verify a downloaded snapshot with:

sha256sum -c SHA256SUMS

Citation

Please cite the original model and technical report when using this release:

@misc{deepseekai2026deepseekv4,
  title={DeepSeek-V4: Towards Highly Efficient Million-Token Context Intelligence},
  author={DeepSeek-AI},
  year={2026},
}