Llama-3.1 Nemotron Ultra 253B vs Mistral Small 3.1 24B Instruct

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.

Mistral Small 3.1 24B Instruct

Mistral AI

Mistral Small 3.1 is a 24-billion-parameter multimodal model from Mistral AI, released in March 2025 as an update to Mistral Small 3 that added vision understanding and expanded the context window from 32K to 128K tokens. The model accepts both text and image inputs, broadening its applicability to document analysis, image-grounded reasoning, and mixed-media workflows without requiring an increase in parameter count. Released under Apache 2.0, it continued Mistral's pattern of incremental capability gains delivered in compact, practically deployable open-weight packages.