Latency numbers every engineer should know
On This Lesson 4 topics
This lesson is planned. The outline below lists the topics it will cover. The full lesson has not been published yet.
In this lesson
estimate costs by order of magnitude.
Planned topics
- Memory access is nanoseconds; SSD reads are microseconds; a same-datacentre round trip is about half a millisecond.
- A cross-continent round trip is on the order of 100 ms or more.
- Each remote call costs roughly thousands of times a local call.
- Chaining calls adds up: five sequential 20 ms calls cost at least 100 ms.
- Numbers shift with hardware; use them for ratios, not precision (verify figures before recording).
Draft outline details
Demonstration
a log-scale bar chart: memory, SSD, same-zone network, cross-region network.
Check your understanding
Five sequential 20 ms calls take at least how long?
Show answer
100 ms.
Practice
Apply this lesson with the module's lab, exercises and quiz.
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