Why you have less than a second to deliver exceptional performancePresentation Transcript
Why you have less than a second todeliver exceptional performance
What is exceptional performance?
I did myhomework
It depends …Instantaneous(0.1 s – 0.2 s)Immediate(0.5 s – 1 s) Continuous (2 s – 4 s)
Websites should load in 2 to 4 seconds
Interactions shouldtake less than a second
What do users say?
Consumer expectations for how How long consumers willquickly a web page should load wait for a page to load before abandoning 5% 1% less than 1 second less than 1 second 1 second 12% 2% 1 second 2 seconds 30% 10% 2 seconds 3 seconds 36% 27% 3 seconds More than 4 seconds 17% More than 4 60% seconds 0% 10% 20% 30% 40% 0% 20% 40% 60% 80%
People are not clocks(i.e. their time perception is not that precise)
The 20 percent rule1.6 s 2s 2.4 s
Exceptionalperformance starts at 1.6 seconds
You might thinkthis is a lot of time
It is not under your control Your control ends here
Web Application Delivery Chain Content Internet ServerBrowser Processing 3rd Party
How much time do you really have?
Bandwidth and Latency
What to expect?http://www.yuiblog.com/blog/2010/04/08/analyzing-bandwidth-and-latency/
Getting web content ContentIcon: http://www.gettyicons.com/free-icon/112/hardware-icon-set/free-server-icon-png/
Adding two round trips we are down to 1.4 seconds
We use more than one domain
We haven’t downloaded anything yet
200 kB at 1.5 Mb/stake about a second
After content download we have 0.3 seconds
What about 3rd Party content
It does not make us faster
Client side processing ~ 0.3 seconds
… we now have 0.0 seconds left …
… and have notconsidered server-side processing
Is it impossible to be exceptionally fast?
No, but it is hard
… really hard
How do we get there?
Do your homework #wpo
… many people don’t
How good are we?
Are we done?
No, we need to look at actual timings
What to look at?
Are we done now?
Now, we need to benchmark
… and optimize again
So now we are done?
We need to optimizeour site for all users
Real User Experience
But now …
We have to do this continuously
“First and foremost, we believe that speed is more than a feature. Speed is the most important feature. If your application is slow, people won’t use it.” “10 Golden Principles of Successful Web Apps” Fred Wilson 19 year Venture Capitalist 3/20/2010http://carsonified.com/blog/business/fred-wilsons-10-golden-principles-of-successful-web-apps/