Llama-3.1 Nemotron Ultra 253B vs Qwen3-Max

Llama-3.1 Nemotron Ultra 253B

NVIDIA

Llama-3.1-Nemotron-Ultra-253B-v1 is a 253-billion-parameter model from NVIDIA, derived from Meta's Llama 3.1 405B using neural architecture search (NAS) compression combined with NVIDIA's Nemotron post-training pipeline, which recovers and exceeds the base model's capability after structural compression. Released in April 2025, it supports toggling between a standard instruction mode and an extended reasoning mode via system prompt, allowing the same model to handle both rapid responses and deliberate chain-of-thought tasks. It is the flagship of the Nemotron family, available open-weight on HuggingFace and through NVIDIA NIM for enterprise inference.

Alibaba / Qwen

Qwen3-Max, released by Alibaba in September 2025 as an API preview, is a large language model exceeding one trillion parameters built for complex reasoning and long-context tasks. It features a 262K token context window, hybrid thinking modes that allow switching between direct generation and extended chain-of-thought, and is available as a proprietary cloud API via Alibaba Cloud and Qwen Chat. Qwen3-Max targets demanding reasoning, multilingual analysis, and applications requiring frontier-level performance from the Qwen3 generation.