Anthropic engineer tests Claude Opus 5.5: 21% faster and 51% cheaper than Fable 5.1 on HAProxy port

Boris Cherny 实测 Claude Opus 5.5：比 Fable 5.1 快且便宜 51%

Anthropic's Boris Cherny has been using Claude Opus 5.5 as his daily driver for weeks. He had both Opus 5.5 and Fable 5.1 port HAProxy from C to Rust. Both passed nearly all tests, but Opus 5.5 finished in 9.5 hours vs. Fable 5.1's 12 hours, at 51% lower cost. Anthropic states Opus 5.5 is the first model in the Claude 5.5 family, matching Fable 5.1 on most tasks while running 40% cheaper than Opus 5.

Why it matters: Cherny's real-world test gives two hard numbers: Opus 5.5 finished the HAProxy port in 9.5h, 51% cheaper than Fable 5.1. Named person, concrete task, direct comparison — more useful than a vendor benchmark. Not 85+ because it's a single-run test, not a generalizable claim.