On GPT-6 Astra, reasoning_effort: "max" costs 2.3x what low costs and returns the same answer on every one of 11 verified tasks; the only setting that changes accuracy is none, which fails 17 of 33 runs (11 tasks, 3 runs each). reasoning_effort is the request parameter that sets how much hidden thinking the model does before it answers; that thinking is billed as reasoning tokens at the output rate, and the ordered values from none to max are the ladder this post measures. The ladder is not the one in the docs: the API's own input check advertises seven values, one of them (minimal) is rejected on every model, and one it never mentions (disabled) is accepted on Astra and does not disable anything. That matters for reading OpenAI's launch benchmarks, reported as "the maximum at any effort": the leaderboard number comes from the most expensive rung of the ladder.
TL;DR
GPT-6 Astra accepts seven reasoning_effort values including none and disabled; the docs list five and say none is unsupported.
none is the only value that zeroes reasoning tokens, and it fails 17 of 33 verified tasks; every other rung scores 33 of 33.
disabled spends 243 reasoning tokens against low's 151 and costs 54% more per correct answer, same accuracy.
