Across 30 shared benchmarks, Claude Sonnet 5 scores higher on 28 and Nemotron 3 Ultra 550B A55B on 2. The widest gap is critpt, where Claude Sonnet 5 scores 16.9 against 3.1. Nemotron 3 Ultra 550B A55B is the cheaper of the two on tracked API pricing ($0.68 against $2.00 per million input tokens).
Best tracked score per model per benchmark (default configuration; source-attributed). ↓ marks lower-is-better metrics. Open either model for its full surface, provenance and pricing. Quoted rates are the price-setter row we currently track for each model — its direct or vendor-official listing where one exists (anthropic-official, direct), otherwise the lowest tracked offer.