The decision to test
Replay a small repository task set and inspect the actual patches and test results. Native endpoint differences matter. A benchmark snapshot does not prove success in your own agent harness.
Three criteria for this comparison
- Complete tool-loop success rate
- Native API migration and streaming behavior
- Cost including retries and discarded answers
Run a fair comparison
Use the same representative inputs and a written answer rubric. Pin the model version and record the endpoint, thinking configuration, quantization when known, context length, output allowance and concurrency. Preserve native request differences in an adapter rather than silently dropping fields.
Measure full request time, error rate and reported usage. For tools, validate arguments and score the result after execution. For images, preserve resolution and preprocessing. A valid response format alone does not establish a correct answer.
Compare cost per accepted result
Calculate input cost plus all billed output, including reasoning where the provider counts it. Add retries and discarded answers. Divide the total by the number of results that pass your quality criteria. Keep API usage cost separate from deployment and engineering cost.
Estimate token costs with the API calculator →