Hey everyone
I’ve been testing different providers in Vapi and noticed something that doesn’t quite match the displayed metrics.
When using:
Provider: OpenAI
Model: GPT 5.1 Instant
I get around:
Cost: ~$0.18/min
Latency: ~975 ms
And the assistant actually feels fast and responsive.
However, when switching to:
Provider: Anthropic (Bedrock)
Model: Claude Sonnet 4
It shows:
Cost: ~$0.10/min
Latency: ~275 ms
But in practice, the assistant takes noticeably longer to respond — significantly slower than GPT 5.1 Instant.
Is this expected?
Are those latency numbers measured differently (e.g. first token vs full response), or could there be something else affecting real-world performance?
Would love some clarification here because the perceived latency doesn’t match the reported metrics at all.
Thanks! 🚀