Frontier AI at a cost: what Anthropic’s Fable 5.1 means for the US-China model race

Anthropic’s powerful new Claude Fable 5.1 model has widened its lead in performance benchmarks over Chinese rivals, even as budget-friendly open-weight models from China continue to gain commercial traction globally. The American company said on Wednesday that Fable 5.1, along with a restricted-access version called Mythos 5.1, was the world’s most advanced model for software coding and complex knowledge work. The standard version scored 66 on Artificial Analysis’ Intelligence Index, taking the.