Equation 2 · OpenAI Model Systems from First Principles: Weights, Post-Training, and Inference Compute
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pretraining compute. Read the equation part by part below; each part has a contextual explanation and a link to its mathematical background.
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subscript
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where is pretraining compute, is post-training compute, Q is the number of served requests over the system’s life, and is the mean compute per request. Until roughly 2024 the third term was treated as approximately fixed for a given model, and public discussion of capability collapsed onto the first. That assumption no longer holds. On current OpenAI models, is a parameter the caller sets: as verified on 8 August 2026, the model guidance documents a reasoninffort control taking the values none , low , medium , high , xhigh , and max , alongside a separate text.verbosity setting [ 2 ] .
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