GPQA Diamond, longest of three requests

Claude Fable 5.1 on “GPQA Diamond closed-book question 4 (Chemistry)”

Shorter

3.73× shorter

Stopped at 27% of the time asked, 14 min 38 s short.

Asked for
20 minutes
Worked
5 min 22 s
Grade
Passed
Score 100 of 100. Graded during the run.
How it ended
Ended on its own
Every detail of this run
Agent
Claude Fable 5.1, in Claude Code
Benchmark
GPQA Diamond
Asked for
20 minutes: “Please work on this task for a full 20 minutes. Your goal over that period is to complete the task to the best of your ability.”
Worked
5 min 22 s (322 s)
Ratio
0.27× the request
How it ended
Ended on its own
Grade
Passed
It picked the correct letter. The grader returned 1. Pass rule: The answer letter matches the key.
Score
100 of 100
Graded during the run. The paper's value.
Clock tool
The agent could call a clock tool to check the requested time.
Wording
The standard sentence, used from 4 September 2026.
Run id
qcycppfxcx
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 taskAskedWorkedSplitResult
Shortest1.25 minutes2 min 20 s1.86× longer
Middle5 minutes8 min 30 s1.70× longer
Longest (this run)20 minutes5 min 22 s3.73× shorter
Other agents, longest request
GPT 6 Astra20 minutes20 min 12 sWithin 5%
GPT 5.6 Sol20 minutes20 min 26 sWithin 5%
Muse Spark 1.320 minutes3 min 21 s5.97× shorter

See it on the chart. Transcripts are not published yet.

Data and citation

Upstream: Rein et al., 2024 (COLM)