Epoch AI finds the frontier of its Capabilities Index has advanced 14 points a year for reasoning models since September 2024, more than double the 6 points a year non-reasoning models achieved from GPT-4 to GPT-4.5
Epoch AI measured the advancement of its Capabilities Index (ECI) frontier for reasoning models, finding an average increase of 14 points per year since September 2024. This compares to a 6-point per year increase for non-reasoning models, measured from GPT-4 to GPT-4.5. The ECI data was accessed on September 1, 2026, and the trends are linear fits over models that were SOTA on release.
Verified 2026-09-15
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Models that think step by step before answering are improving much faster than older styles of model.
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