Gemini 4 Carbon Tops MathArena but Costs 15 Times More Than GPT-6.1 Sol

By Matthias BastianOriginal title: Gemini 4 Carbon takes the MathArena crown but costs 15 times more than GPT-6.1 Sol
78AI Score

Google's Gemini 4 Carbon has become the first non-OpenAI model in a while to top the MathArena math benchmark, displacing GPT-6.1 Sol, with Anthropic's Claude Fable 5.2 taking second place. However, its evaluation cost runs roughly 15 times that of GPT-6.1 Sol, and its most common failure mode is exceeding the time limit while almost never abandoning a task. The best open model, Moonshot AI's Kimi K3.1 Pro, trails at 54.3%.

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Gemini 4 Carbon takes the MathArena crown but costs 15 times more than GPT-6.1 Sol

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  [Matthias Bastian](https://the-decoder.com/author/matthias-bastian/) [View the LinkedIn Profile of Matthias Bastian](https://www.linkedin.com/in/matthias-bastian-128b71b1/)   Nov 14, 2026          

Google's Gemini 4 Carbon has become the first non-OpenAI model in a while to top the MathArena math benchmark. It knocked GPT-6.1 Sol from the top spot, while Claude Fable 5.2 came in second, making it potentially one of the most capable publicly available models for math tasks. OpenAI's models, which recently allegedly solved demanding equations like the Navier-Stokes equations, aren't publicly available yet.

Gemini 4 Carbon's most common failure mode is exceeding the time limit. The model also almost never gives up on a task, a trait that can be read as either positive or negative. In one case, it launched a script that ran for more than eleven hours without checking on its progress. That extra performance comes at a price, though. With the reasoning settings used in testing, Carbon and Fable 5.2 cost roughly 15 and 40 times as much as GPT-6.1 Sol, respectively.

RecommendationModelProviderRelease dateExpected performanceExpected cost
#1 overallGemini 4 Carbon (high)GoogleNovember 10, 202685.4% ±3.0%$15.70 ±$1.33
#2 overallClaude-Fable-5.2 (max)AnthropicNovember 9, 202682.8% ±5.3%$40.20 ±$2.59
#3 overallGPT-6.1 Sol (max)OpenAISeptember 29, 202680.6% ±2.7%$1.07 ±$0.018
Best open modelKimi K3.1 Pro (max)Moonshot AIOctober 23, 202654.3% ±5.8%$3.70 ±$0.27

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