Claude Mythos Destroys GPT 5.5 on Shared Benchmarks — 138 Upvotes, 121 Comments on r/singularity

r/singularity·high signal

Hours after GPT 5.5's launch, r/singularity erupted with benchmark comparisons showing Anthropic's restricted Claude Mythos Preview outperforming GPT 5.5 across shared evaluations. Mythos scores 93.9% on SWE-bench Verified vs. GPT 5.5's 88.7%, and 97.6% on USAMO 2026. The 121-comment thread debates whether Anthropic's decision to restrict Mythos access (citing cybersecurity risks) gives them a strategic advantage — the model exists as a capability ceiling without being commercially available.