Research|LLM: Gemini 4 Carbon Puts Google Back in the Lead as RSI Accelerates Model Development

Executive Summary

1. Google announced Gemini 4 Carbon on October 28, about two weeks after Argon became broadly available on October 13. On version 5 of the Artificial Analysis (AA) Intelligence Index, Carbon ranks first with a score of 59, ahead of Claude Opus 5.5 at 58 and GPT-6 Astra at 57; Argon scores 50. Pricing matches Argon: introductory rates of $2 per million input tokens and $10 per million output tokens, rising to standard rates of $4/$20. All token prices below follow this input/output convention. Carbon is initially being made available to a select group of cyber defenders, with access then expanding to more partners through the Fairwind Program. Google has not announced when developers and consumers will get access.
2. Google is back in the top tier. With models from the three leading labs separated by just two points on the AA index, we believe competition in model training has intensified further. Consistent with our earlier view, Alphabet CEO Sundar Pichai said on the company’s earnings call the same day that AI is helping Google speed up model training and releases. He expects recursive self-improvement (RSI) to drive further acceleration over the next 12 months. Our understanding is that Google used model soups in this cycle to accelerate model development.

Benchmarks: First Overall, Still Behind Opus 5.5 in Coding

Google benchmark comparison for Gemini 4 Carbon (selected)