DeepSWE v1.1, longest of three requests

Claude Fable 5.1 on “Add hierarchical evaluation cancellation to Boa”

Shorter

3.10× shorter

Stopped at 32% of the time asked, 1 h 25 min short.

Asked

Worked

Safety cutoff 4 h 10 min, off the scale

Every detail of this run

Agent: Claude Fable 5.1, in Claude Code
Benchmark: DeepSWE v1.1
Task: Add hierarchical evaluation cancellation to Boa
Asked for: 125 minutes: “Please work on this task for a full 125 minutes. Your goal over that period is to complete the task to the best of your ability.”
Worked: 40 min 16 s (2,416 s)
Ratio: 0.32× the request
How it ended: Ended on its own
Grade: Passed; It passed its hidden tests. The grader returned 1. Pass rule: The hidden tests pass.
Score: 100 of 100; Graded during the run. The paper's value.
Wording: The standard sentence, used from 4 September 2026.
Run id: fcynhgo6a3
Data release: 26 Sep 2026

The other requests for Claude Fable 5.1 on this task, and the other agents at this request
Fable on this task	Asked	Worked	Result
Shortest	8 minutes	31 min 9 s	3.89× longer
Middle	30 minutes	45 min 22 s	1.51× longer
Longest (this run)	125 minutes	40 min 16 s	3.10× shorter
Other agents, longest request
GPT 6 Astra	125 minutes	2 h 8 min	Within 5%
GPT 5.6 Sol	125 minutes	2 h 6 min	Within 5%

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