Fable 5.1 vs. Fable 5: Results on a real-world budget, not the spec sheet
The New Stack 1 month ago 17 ● 2 sources
Anthropic’s Claude Fable 5.1 posted a higher Terminal-Bench-Science result than Claude Fable 5, but an independent test of the benchmark’s tasks under a fixed user-like budget found a much smaller gap. In the sampled runs with a $12 limit and 60 turns per test, Fable 5.1 solved 1 task where Fable 5 solved 0, with total cost $40.75 vs $53.59 and total time 262 min vs 388 min. The benchmark’s claimed doubling did not translate into a similarly large advantage for average-style runs, and differences mostly showed up in cost and whether the model hit the imposed budget limit.