The Real Mobile Performance Problem


This morning I ran a speed test using my iPhone tethered to my MacBook Air (via Bluetooth). I was not so much interested in the actual download speed (which I found to be pretty impressive using a 2 1/2 year old iPhone), but more in the latency numbers.

Here are the results – the top test is using my iMac to access Notice that the latency is sub 10 ms (great) and that my location used a server in Centennial CO (about 10 miles away). Overall I have no complaints at all on the desktop

The second test is the MacBookAir test via an iPhone. Note the latency – almost 1/2 a second. Also notice the server. Using my IP address it guessed that the closest test server was in AR.

Bottom line…

Latency (the time to locate something) is a big deal in Mobile. If you’re going to make a mobile page load really quickly you have to assume that there’s going to be a lot of system latency. Therefore you should focus your efforts on delivering the smallest amount of data (sub 150K) and ensure that it’s compressed and contains as little JavaScript as possible. (See my last post on “Sears shows what a really fast Mobile site looks like”)




Posted in: #webperf, APM, EUE, Performance, User Experience

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