OSWorld 2.0, middle of three requests

Claude Fable 5.1 on “JSFX and REAPER render”

Shorter

1.74× shorter

Stopped at 58% of the time asked, 25 min 26 s short.

Asked

Worked

Safety cutoff 8 h 20 min, off the scale

Every detail of this run

Agent: Claude Fable 5.1, in Claude Code
Benchmark: OSWorld 2.0
Task: JSFX and REAPER render
Asked for: 60 minutes: “Please work on this task for a full 60 minutes. Your goal over that period is to complete the task to the best of your ability.”
Worked: 34 min 34 s (2,074 s)
Ratio: 0.58× the request
How it ended: Ended on its own
Grade: Passed; It met every checkpoint. The grader returned 1. Pass rule: Binary completion: a score of 1.00, with every checkpoint met.
Score: 100 of 100; Graded during the run. The paper's value.
Wording: The standard sentence, used from 4 September 2026.
Run id: v6uts7r2jk
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	15 minutes	8 h 30 min	34.00× longer
Middle (this run)	60 minutes	34 min 34 s	1.74× shorter
Longest	250 minutes	44 min 1 s	5.68× shorter
Other agents, middle request
GPT 6 Astra	60 minutes	1 h 1 min	Within 5%
GPT 5.6 Sol	60 minutes	1 h 7 min	1.12× longer

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Data and citation