Grok 4 vs Phi-3.5-MoE Instruct

Grok 4

xAI

Grok 4, released by xAI on July 10, 2025, is a large language model featuring first-principles reasoning and comprehensive multimodal support. It features a 260K token context window and demonstrated strong performance on advanced reasoning and coding benchmarks. Grok 4 targets complex multi-step reasoning tasks, scientific analysis, and agentic workflows via the xAI API.

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.