Arena: Gemini 4 Hydrogen is the fastest model in the Agent Arena top 10

Arena says Google's Gemini 4 Hydrogen is the fastest model in the Agent Arena top 10, with a typical step taking 7.3 seconds. By Arena's figures that is about 2.7x faster than Claude Sonnet 5.5 and 3.1x faster than GPT-6.1 Sol.

• Across Agent Arena sessions, Hydrogen finishes 82% of its tasks in under 10 minutes, against 55% for GPT-6.1 Sol and 44% for Claude Sonnet 5.5. Within 30 minutes the shares are 97%, 81% and 78%.
• Arena says Hydrogen's net improvement is on par with both models, so the speed is not a quality trade-off.
• Arena counts a step as one model API call in an Agent Mode task, timed from the first model request to the last streamed reply, without tool execution.