title: "Latency Expectations and Performance Metrics",
summary:
"Expected latency ranges, the main variables that influence them, and how DevSpeak keeps long-running flows bounded.",
category: "core-translation-engine",
tags: [
"latency",
"performance",
"fast-ai",
"document-jobs",
"provider-fallback",
],
lastReviewed: "2026-10-18",
};
Latency Expectations and Performance Metrics
DevSpeak is optimized for practical engineering work, which means latency varies by request shape. Short text translations, Fast AI live corrections, and large document jobs do not use the same execution path or timing envelope.
Relative Cost of Each Flow
Generation time depends on provider availability, input size, and whether files are involved, so DevSpeak does not publish a fixed figure. What is stable is the _relative_ cost of each flow, ordered fastest to slowest.
| Flow | Relative Cost | Why |
| :---------------------------- | :------------------ | :--------------------------------------------------------------------------------- |
| Fast AI live correction | Fastest per request | Sends only the changed sentences and returns a corrected copy, not a full document |
| Concise standard translation | Fast | Lower prompt expansion, shorter outputs |
| Detailed standard translation | Moderate | More structured output and larger responses |
| Async document translation | Slowest | Depends on file size, extraction, and chunk count |
Every completed translation records its own measured latency in History, so your own runs are the authoritative reference for your workload.
What Drives Latency
Input size: Longer source text or more complex instructions increase generation time.
Output depth: Detailed prompts produce more structured output than concise requests.
Attachments: Images, PDFs, and uploaded documents add preprocessing and compatibility constraints.
Provider routing: The managed path, BYOK resolution, automatic router recommendation, and fallback behavior can change the request path. Routing analysis itself adds no perceptible latency.
Document chunking: Async translation jobs process work in bounded chunks instead of a single unbounded request.Performance Signals DevSpeak Keeps
Latency: Stored with translation history for later comparison.
Word count: Used as a practical indicator of output size.
Job progress: Async document flows track chunk progress and completion state.
Health checks: The platform records service-level status outside the main user workflow.How the Platform Keeps Requests Bounded
Fast AI: Sends only the sentences you changed, cancels a request as soon as you edit its sentence again, and sends nothing above 20,000 characters.
Automatic recovery: If the model serving your request is unavailable, another one takes over rather than the request failing. Recovering this way adds time to that request.
Abort controls: You can stop a generation that is already running.
Large documents: Document translation is processed in sections, so a long job keeps progressing and can resume rather than restarting.Practical Guidance
Use concise mode when you need a fast technical rewrite rather than a full spec.
Use Fast AI to clean up the wording of a request, then press Translate for the full spec.
Keep attachments relevant and well-scoped.
Prefer document jobs for large source files instead of forcing everything through the text path.