Gemini 4 Carbon vs GPT-6 Astra: benchmarks and token cost

This comparison uses Gemini 4 Carbon (High) and GPT-6 Astra (Max). It reports the captured benchmark data, with no new hands-on test.

Carbon pairs a higher index with lower token rates

Carbon has the higher captured overall index, 59.4 versus 56.9, while its listed input and output rates are $4 and $20 per million tokens, compared with Astra’s $10 and $50. That combination makes Carbon a useful cost-and-score baseline. Astra still needs a workload-specific evaluation; the available snapshot does not contain separate coding or math results to settle those uses.

How to read the table

The intelligence index is an aggregate measurement, not a percentage of correct answers in your application. Input and output prices are separate rates per million tokens. Coding and math indices are unavailable in this capture and must not be read as zero. Compare first-token latency separately from output-token throughput, and use the same model effort settings for a trial. Choose using task quality, total time and the cost of accepted results; provider features and deployment requirements need their own checks.