Cool as she is, the iPhone 4S' new personal assistant Siri hasn't been able to tell me in a meaningful way which iPhone 4S offers the fastest data speeds. In the end, I resorted to the usual do-it-yourself approach: a real-world test. And the results were interesting.
Prior to the testing, I expected some big differences between the iPhone 4 and the iPhone 4S (both GSM versions), since the iPhone 4S supports AT&T's faster HSDPA 14.4 network, which is capable of reaching an upload speed of 14.4Mbps and download speed of 5.8Mbps, theoretically twice the speeds of the iPhone 4.
This wasn't always the case, however, and sometimes it was quite the opposite. But first let's talk about how the testing was done.
How we test It's generally hard to figure out the way to get the best picture of how fast a mobile cellular Internet device's data rate is. The truth is that the speed of a cellular Internet connection varies a great deal from one location to another. It also depends on the server on which the app's data resides and sometimes even on the time of day.
For the testing, I used the Speedtest.net mobile app, which is the most popular app for the purpose. The app automatically connects to a nearby server to download and upload data. How busy the server is during the test affects the scores, but the app still offers a good representation of data speeds in a local area.
I gathered iPhone 4Ses from AT&T, Verizon, and Sprint, and tested the three smartphones against an iPhone 4 at a few well-known places in San Francisco: CNET's lobby, Union Square, and the Fisherman's Wharf area of Pier 39. I picked the first location for an obvious reason: it's the lobby of the building where I work, which is near the Financial District. The others are two of the most popular spots in the city, with lots of people using their phones. Also, I tested three 4G hot spots from various carriers for a comparison.
Keep in mind that these tests only evaluate data speeds for these phones in San Francisco and are not designed to be representative of data speeds you'll find in your area. However, they at least should show how the data speeds compare between each carrier version of the iPhone 4S, as well as the difference between AT&T's iPhone 4S and the iPhone 4.… Read more