Edge 2016 what slows you down - your network or your device

© AKAMAI - EDGE 2016

What slows you down? Your network or your device?

Moritz Steiner, Web Performance Foundry


web performance

metric: page load time

network: time to first byte, object load time

device: socket IO, parsing, layout, script execution, painting...

page: payload, complexity


mobile = device + network

mobile = small device + cellular network

network: latency, jitter, bandwidth fluctuation, power statedevice: 8x-10x slower compared to laptops


impact on the network (mostly)


impact on the device (mostly)


chrome developer tools for desktop

● office LAN● 266 requests● 2.2 MBytes

transferred● 1.55s PLT


device activity

significant fraction of time spent with script evaluation and rendering


chrome developer tools for android

● usb tether an android or iOSdevice

● browse to chrome://inspect

● allow debugging● uses the phone’s

connection


network activity

● LTE● 201 requests● 1.7 MBytes

transferred● 12.39s PLT

● 8X slower than desktop


device activity

more absolute time spent with parsing, scripting, rendering, and idling


compare network and device activity

desktop mobile

loading 0.03 0.6

scripting 0.3 5.2

rendering 0.1 2.3

painting 0.4 0.4

network 0.5 2.0

up to 20x


network and computation in perspective

network computation


fraction of time spent on processing

Demystifying Page Load Performance with WProf, University of Washington, NSDI 2013


performance comparison (active experiments)

3s median

5.1s median 5.4s median


performance trends (RUM data)


performance trends (active experiments)


network performance comparison (RUM data)

4 major cellular ISPs and 1 FTTH provider in the US


Accelerated Mobile Pages AMP

• Subset of HTML• Gets rid of javascript• Inlines CSS• Eliminates most 3rd parties


• mobile web performance dependso on the networko on the device

• develop and test in real conditionso real (low powered) deviceso real cellular networks

• think twice about those js libraries

summary

Technology

Edge 2016 what slows you down - your network or your device