Claude Opus is 10x faster than OpenAI GPT 5 at non-streaming completions

A developer compared non-streaming completion latency across Claude claude-opus-4.8, OpenAI gpt-5, and gpt-5-mini for a real-world blog comment rewriting task. Claude was nearly 10x faster than gpt-5, while gpt-5-mini was both faster and cheaper than gpt-5 (3x price difference). As a bonus, the author also measured a latency difference between using the litellm wrapper versus the native OpenAI SDK, and decided to drop litellm in favor of native SDKs partly due to recent CVEs.