diff --git a/docs/HyperlinkedInformation/UnderstandingTiming.md b/docs/HyperlinkedInformation/UnderstandingTiming.md index 7e31335..86b9c88 100644 --- a/docs/HyperlinkedInformation/UnderstandingTiming.md +++ b/docs/HyperlinkedInformation/UnderstandingTiming.md @@ -1,14 +1,15 @@ This document explains useful things about the "Timing" tab. -## First, The Warnings +## Be Cautious And Sceptical -There are two issues with the numbers displayed in the "Timing" tab: +There are two issues with the numbers: 1. Accurately timing something in the browser is almost a fool's errand. One moment it takes 1ms and the next it takes 10ms, and you’ll never know why. Noisy. - So, do not ever believe one set of timings numbers. + So, don't ever base decision on one set of timings. Run + the same event at least a few of times. In the future, we'd like to add a 'Run It Again' button, which you can click a few times to see if you get stable numbers. @@ -17,28 +18,28 @@ There are two issues with the numbers displayed in the "Timing" tab: 2. Don't freak out about any apparent slowness, yet. - You're currently running a dev build, right, not the - production build? - And I'm guessing you're also running a dev build - of React? + After all, you're running a dev build, right, not the + production build? And I'm guessing you're also + running a dev build of React? - Also, using `re-frame-trace` will slow things + And using `re-frame-trace` will slow things down too, what with all that creating and analysing of trace. So, run the production version of your app first before deciding you have a performance problem. Something that takes 100ms in dev might take 20ms in prod. - This Timing panel is not really about absolute numbers so - much as the relative time taken to do the "parts" of an Epoch. - And, even then, be cautious of these relative numbers because - of point 1 (above). + This Timing Tab is not really about absolute numbers so + much as the relative time taken to do the different + "parts" of an Epoch. Is one View ridiculously slow for some + reason, compared to others? + And, even then, remember point 1 (above). ## Know Your Epoch Timeline You'll understand the contents of the Timings tab better if you understand how an event is processed over time within the browser. -The following infographic might help: +The following infographic will help: