Speed, Performance, and Human Perception
summary
Performance is not just milliseconds or kilobytes but a three-part function: actual system latency, wetware expectations, and UX that ties them to task completion. Humans perceive under 100 ms feels instant, notice delays around one second and abandon after ten, visual work needs 16 ms for 60 fps while 24 fps is barely acceptable and audio detects ~1 ms jitter. Examples: a page that renders in 500 ms can still take 5–10 s to read (Hacker News), ultra‑fast signup looks broken (fixed with a short spinner), and analytics need fast/slow‑path feedback (estimate seconds, not GB).
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chapters (6)
- 0:00Start
- 0:03Speed Performance and Human Perception
- 10:19Render Time
- 13:59Optimizing Perceived Performance
- 14:45Perceived Performance
- 15:07What Are the Technical Performance Constraints
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