OpenAI’s open‑weight large language model- gpt‑oss‑120b

 The gpt‑oss‑120b is one of OpenAI’s newly released open‑weight large language models (as of August 2025). It is designed to offer high reasoning and coding performance, while being freely available for download and use, including fine-tuning and commercial deployment.

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🔍 Overview of gpt‑oss‑120b

Feature	Description
Model type	Mixture-of-Experts (MoE)
Total parameters	~120 billion
Active parameters	~12.7 billion per forward pass
Number of layers	36 transformer layers
Experts per layer	128 experts
Experts activated	4 per token
Context window	128,000 tokens
License	Apache 2.0 (permissive, commercial use allowed)
Release date	August 5, 2025
Performance	Comparable to OpenAI's proprietary GPT-4o-mini
Hardware support	Optimized for multi-GPU systems (e.g., 4×A100, 8×H100), also available via Hugging Face, Databricks, and AWS

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⚙️ How It Works (Mixture-of-Experts)

• In a Mixture-of-Experts architecture:

  • Each layer contains 128 separate expert networks.

  • For each input token, only 4 of those experts are activated.

  • This makes the model more efficient (lower compute cost) while preserving high performance.

This sparse activation allows the model to scale to 120B total parameters without requiring the compute of a dense 120B model.

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🧠 Capabilities

• High performance on benchmarks:

  • Reasoning: MMLU, ARC, and Big-Bench Hard

  • Math: GSM8K

  • Coding: HumanEval, MBPP

  • Health: HealthBench

• Handles long documents and conversations (128K token context)

• Effective at:

  • Chain-of-thought reasoning

  • Tool use

  • Instruction following

  • Summarization and question answering

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🛠️ How You Can Use It

• Download and run locally (with strong enough hardware)

• Fine-tune or customize on your own data

• Deploy via cloud platforms:

  • Hugging Face

  • Databricks

  • AWS Bedrock/SageMaker

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🔐 Safety & Policy

• Released after extensive safety testing including simulated misuse, red-teaming, and external evaluations.

• Not a fully open-source model (training data and pretraining code are not released), but open weights mean you have full access to the model for any use case, under the Apache 2.0 license.

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📦 Where to Get It

• Direct download from OpenAI’s GitHub (or via Hugging Face and other ML model hubs)

• Works with:

  • Transformers libraries (transformers, vllm)

  • Tools like LangChain, LlamaIndex

  • Popular inference backends like vLLM and TGI

https://amzn.to/4lmPQWV