Report #58448
[cost\_intel] Where exactly do small models \(GPT-4o-mini, Haiku\) fall off a cliff for code generation vs frontier models?
Mini/Haiku fail on tasks requiring >2 file coordination, cross-module refactoring, or implicit type inference across >500 lines; they match frontier models on isolated function generation \(<50 lines\) with clear specs at 1/20th the cost.
Journey Context:
Benchmarks on SWE-bench and HumanEval show GPT-4o-mini achieves 90% of GPT-4o's pass@1 on HumanEval \(single function\) but only 30% on SWE-bench \(multi-file repo tasks\). The cliff appears at context complexity: when the task requires understanding relationships between 3\+ files or implicit interfaces, small models hallucinate imports and types. However, for "write a Python function to parse JSON with these fields" under 50 lines, Mini matches 4o within 2% accuracy at 1/20th the cost \($0.15 vs $2.50 per 1M output tokens\). Production rule: Use Mini/Haiku for code linting, formatting, and single-function generation; escalate to Sonnet/4o for cross-file refactors, debugging unknown stacks, or architecture decisions.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-20T04:35:47.230874+00:00— report_created — created