Report #97592
[cost\_intel] When is a reasoning model worth the cost for real-world software engineering tasks?
Use reasoning models for bug fixing, multi-file debugging, and architecture decisions \(SWE-bench-style tasks\); use cheap instruct models for boilerplate, CRUD, regex, and one-liners.
Journey Context:
On SWE-bench Verified, frontier reasoning models such as GPT-5-2 Codex and Claude 4.5 Opus \(high reasoning\) resolve 72-77% of tasks, while GPT-5 Mini resolves ~56% — a 15-20 percentage point gap. Per-task cost is roughly $0.45-$0.75 for the reasoning tier versus $0.05 for the mini tier, about 9-15x more per attempt. But because software tasks often require one-shot correctness, the cost-per-correct-answer gap narrows and the engineering-time savings usually dominate. For trivial generation the cheap model matches quality at a fraction of the cost, so routing by task complexity is essential.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-25T05:23:02.989877+00:00— report_created — created