StepFun releases Step 5 Preview open weights model
MarkTechPost: StepFun Releases Step 5 Preview Open Weights: 600B MoE, 27B Active, 1M Context
StepFun has released Step 5 Preview as open weights. FP8 and BF16 checkpoints are live on Hugging Face and ModelScope. Step 5 Preview is a sparse Mixture-of-Experts model from StepFun built for long-horizon agentic work. It has 600B total parameters, 27B active per token and up to 1M tokens of context. For developers, this is a new self-hostable option for coding agents, document analysis and finance workflows. TL;DR Size: 600B total, 27B active per token, up to 1M-token context. Runs
Get smart on it
StepFun has released an open-weights artificial intelligence model called Step 5 Preview, which is designed to handle long-context tasks like coding, document analysis, and finance work. The model contains 600 billion total parameters but only activates 27 billion per token, allowing it to run on data-center GPUs while supporting up to 1 million tokens of context. Performance varies across benchmarks, with strong results on long-context reasoning tasks but weaker performance on some specialized benchmarks compared to competing models. The model is available in two formats on Hugging Face and ModelScope, or users can access it through an API priced at $1.00 per million input tokens and $2.70 per million output tokens.
Explainer: What Is a Mixture of Experts Model and Why Does It Use Fewer Resources?
Relevant courses
Want to go deeper than the news? Explore live, cohort-based AI courses taught by practitioners.
Browse AI courses on MavenRelated news
Welcome Muse Spark Open: open-weight frontier multimodal mixture-of-experts model from Meta
Open-weight models let researchers and companies build AI systems without relying on proprietary providers, potentially accelerating innovation across industries.
Also reported by The Verge, The Decoder, TechCrunch and SiliconANGLE
Gemini 4 Argon is now available worldwide as Google's most capable frontier model
Google is making Gemini 4 Argon available worldwide through its API, the Gemini app, and Google Antigravity. The frontier model is aggressively priced but trails Anthropic's Claude Opus 5.5 and Meta's Muse Wonder Full in independent benchmarks. Internally, Google says Argon already cut coding tasks from months to weeks. The article Gemini 4 Argon is now available worldwide as Google's most capable frontier model appeared first on The Decoder.
Also reported by Google DeepMind, SiliconANGLE and MarkTechPost
OpenAI will reportedly ship at least one model this year but its flagship still needs alignment work
OpenAI is racing to finish its next flagship model, which uses the same looped transformer technique as Astra to boost math and coding performance. The tradeoff is that looping makes safety monitoring harder. Microsoft accidentally revealed details about how the technique works on a public page. Whether or not the flagship is ready in time, employees say one or two new models will likely ship by year's end. The article OpenAI will reportedly ship at least one model this year but its fla
Open From Data Center to Desktop: NVIDIA Expands Nemotron Family With Highest Efficiency Super VL and Bolt Models
NVIDIA today released Nemotron 3.5 Super VL, an open 120-billion-parameter model that delivers the fastest task completion and highest accuracy for specialized always-on agents. Joining it are two new edge models: Nemotron 3.5 Bolt 74B-A9B 24GB, optimized to balance intelligence and speed per GB for local agentic workloads, and Nemotron 3.5 Bolt E4B 4GB, optimized for intelligence per GB for fast conversational agents. Super VL and Bolt 74B-A9B are available now, with Bolt E4B coming Oct. 23. T
Also reported by The Decoder, SiliconANGLE and MarkTechPost
Microsoft reveals cutting-edge MAI-Base-2 model with 2T parameters
Microsoft Corp. has developed a new large language model that it says is significantly more efficient than leading open-source alternatives. The company’s artificial intelligence research group detailed the algorithm on Thursday. MAI-Base-2 is not a full-fledged LLM but rather a base model, a kind of no-frills prototype. Developers turn base models into LLMs by putting […] The post Microsoft reveals cutting-edge MAI-Base-2 model with 2T parameters appeared first on SiliconANGLE.
Reflection AI open-sources Beam’s weights, post-training recipes
Startup Reflection AI Inc. today made the weights of Beam, its first large language model, available on Hugging Face. The company also released technical resources that will enable developers to customize the algorithm. Originally introduced last week, Beam is one of the industry’s most advanced open-source LLMs. It features about 500 billion parameters, yet approaches […] The post Reflection AI open-sources Beam’s weights, post-training recipes appeared first on SiliconANGLE.