GPT-5 vs Phi-3.5-MoE Instruct

GPT-5

OpenAI

GPT-5, released by OpenAI on August 7, 2025, is a large language model that combines direct generation and extended reasoning in a single unified system with a built-in routing mechanism. It features a 400K token context window, 128K maximum output tokens, native multimodal support (text, image, audio, video), and demonstrated strong results across coding, mathematics, visual understanding, and health benchmarks at release. GPT-5 targets complex multi-step tasks including advanced coding, mathematical problem solving, and long-context analysis.

Phi-3.5-MoE Instruct

Microsoft

Phi-3.5-MoE-instruct is a sparse mixture-of-experts model from Microsoft's Phi research team, released in August 2024 with 42 billion total parameters across 16 experts and approximately 6.6 billion active parameters per forward pass. The model applies Microsoft's small-data, high-quality training philosophy — developed across earlier Phi generations — to a MoE architecture, targeting reasoning quality comparable to much larger dense models at a fraction of the inference compute. Released under the MIT license, it was notable in the research community for demonstrating that MoE efficiency gains could be realized at smaller total parameter counts than typical large-scale MoE deployments.