xAI releases Grok 4.6 on Colossus supercluster

xAI has made Grok 4.6 generally available, trained on the Colossus supercluster in Memphis with over 200,000 accelerators. The model adds a Deep Reflection Engine, a 2-million-token context window and unified multimodal attention.

• Colossus in Memphis runs over 200,000 H100 and H200 accelerators
• Grok 4.6 has a 2-million-token context window
• Deep Reflection Engine runs tree search over hypotheses before answering
• Training used RLFV with verification in Lean 4, Coq and Isabelle/HOL