InfluxData Developer Content Writer Jessica Wachtel Independent Test: GPT-6.1 Terra's Numerical Aggregation Accuracy Is Only Half That of Astra, But It Returns Uncomputed Queries to the User
OpenAI claims that GPT-6.1 Terra reaches parity with its flagship Astra model on the Agents' Last Exam benchmark at one-tenth the price. Developer content writer Jessica Wachtel independently tested three synthetic task sets and found that while both models tied in event triage, Terra scored only 26/50 on SQL aggregation tasks compared to Astra's 48/50. Terra's failure mode was not fabricating numbers, but rather returning the most difficult calculation parts to the user, assigning the same confidence level to incorrect answers as it did to correct ones.
When OpenAI released GPT-6.1 Terra on October 26, it claimed the model performed comparably to its flagship GPT-6 Astra on the Agents' Last Exam benchmark, while costing only one-tenth per token. Jessica Wachtel, a developer content writer at InfluxData, decided to independently verify this claim using three sets of synthetic tasks. She ran each model once through the OpenAI API with high reasoning effort settings and found that the claim does not hold true across all task types.
The widest divergence appeared in SQL reasoning tests: she constructed a fake database containing 500 software build records and posed 25 questions covering soft deletes, retries, three currencies, and time zone dependencies. Astra scored 48/50, while Terra scored 26/50. Terra processed all 500 rows and correctly handled soft deletes and retries, but on six questions requiring cost or duration aggregation across all rows, it did not attempt to provide an answer. Instead, it wrote out SQL queries for the user to run themselves, marking them as 'not calculated.' Wachtel noted this was the first time she had seen AI hand work back to the user.
More concerning is another failure mode exhibited by Terra. In the SQL test, it answered six questions incorrectly, four of which involved count deviations of only one or two. Terra assigned the same confidence levels to these incorrect answers as it did to its correct ones, providing no signal that they might be wrong. If these figures were used directly in reports, users would have no way of knowing which data points required verification.