Time to First Token: How Long Does It Take for a Large Model to Start Responding?
When using large language models, we typically have two perceptions of “speed”: one is how long it takes for the first character to appear after a question is posed; the other is whether the text generated after the response begins flows smoothly. This is similar to a conversation with a person: after you ask a question, the other person might pause before speaking. Time to First Token (TTFT) measures this “wait time before speaking.” We can explain this clearly from three perspectives.
