[rrjamie]

The big killer here, especially on 3G/LTE, is latency not throughput. Here in Vancouver, I can get 40Mbit down on LTE, but my ping is in the 300s.

Here's a pretty good post on how latency dominates page load speed after a certain point: http://www.igvita.com/2012/07/19/latency-the-new-web-perform...

By bundling resources, we reduce the number of requests, and the number of round trips.

Disclaimer: I work at Mobify with Peter who authored the post.

[shoebappa]

But wouldn't 300ms for one request and 300ms for 6 concurrent requests all have the same latency?

[rrjamie]

In the ideal case, sure.

However, according the HTTP archive websites make about ~90 requests per page [1]. The average browser does about 6 requests per hostname, and 15-20 total [2]. In this situation, our critical path has at least 4 requests, thus we are paying 4xRTT in just latency.

edit: formatting

[1] http://httparchive.org/trends.php

[2] http://www.browserscope.org/results?o=xhr&v=top&cate...