阶跃星辰（StepFun）发布 Step 5 Preview 开放权重，BF16 与 FP8 权重已上线 Hugging Face 和 ModelScope。模型为稀疏 MoE，总参数 600B、每 token 激活 27B，支持 1M token 上下文窗口和原生文本与视觉输入，面向编码、软件工程、专业知识和金融等长程智能体任务。
同一新闻，精选展示《阶跃星辰开放 Step 5 Preview 权重，600B MoE 支持 1M 上下文》
Congrats to StepFun on Step 5 Preview 🙌 Their largest open weights release.
The 600B MoE model is built to handle agent tasks lasting up to 24 hours.
The model runs at nearly 8K tokens/sec/GPU on NVIDIA GB300 using NVFP4.
NVP4 checkpoint: https://huggingface.co/stepfun-ai/Step-5-Preview-NVFP4
Deploy with @SGL_project - https://docs.sglang.io/cookbook/autoregressive/StepFun/Step-5-Preview or @vLLM_project - https://recipes.vllm.ai/stepfun-ai/Step-5-Preview
Post-train with NeMo Automodel: https://github.com/NVIDIA-NeMo/Automodel/blob/main/docs/model-coverage/llm/stepfun-ai/step-5-preview.mdx
Run it with NVIDIA NIM using a single command: https://catalog.ngc.nvidia.com/orgs/nim/nvidia/containers/vllm-model-free-nim-experimental/-
Step 5 Preview is now open weights. BF16 and FP8 weights are live on Hugging Face and ModelScope, together with our technical blog. • Sparse MoE: 600B total, 27B active per token • 1M-token context window • Native text and vision input • Built for long-horizon agentic work: coding, software engineering, professional knowledge work and finance Frontier intelligence, open weights. Build what's next. Hugging Face: https://huggingface.co/stepfun-ai/Step-5-Preview ModelScope: https://modelscope.ai/models/stepfun-ai/Step-5-Preview GitHub: https://github.com/stepfun-ai/Step-5-Preview在 X 查看被引用的帖子
来源：NVIDIA AI · x.com