xAI Grok 3 Review — The Model That Topped the Arena (Before Grok 4 Landed Four Months Later)

Grok 3 launched February 17, 2025 as xAI's most capable model to date, trained on 200,000 H100 GPUs with 10x the compute of Grok 2. It topped the LMArena leaderboard at Elo 1402 — the first model to cross 1400 — and posted 93.3% on AIME 2025 with Think mode. We review what it got right, where it fell short, and why Grok 4 superseded it in five months.