Which phone is fastest?

In our recent 13-city speed tests, we declared T-Mobile the fastest in our smartphone-based tests. However that was previously the arrival of Verizon's 4G LTE (Long Term Evolution, latest standard in the mobile network technology) ThunderBolt. The phone clocked download speeds that were more than five times faster than T-Mobile's Galaxy S 4G, and about eleven times faster than AT&T's Atrix.

The LTE phone's overall average upload speed came in at 7.39 mbps, more than six times the upload speed of the second-place finisher, T-Mobile's Galaxy S 4G. With speeds of the same type, even high-bandwidth bidirectional apps just as video chat and online gaming perform as they do when hooked up with a fat broadband cable.

Network latency, or the time needed for a single packet of data to travel through the network, was as well exceedingly low on the Verizon LTE network at 57 milliseconds, meaning that the network has very little congestion or bottlenecking at this time. Latency times of less than 100 milliseconds are ideal, during delays of more than 200 milliseconds can limit throughput and impair real-time services just as VoIP (Voice over Internet Protocol) and videoconferencing.

In our January speed tests, we discovered that Verizon LTE USB modems, which the company had begun selling then in advance of its first LTE smartphone, were hitting download speeds and upload speeds that were twice as fast as T-Mobile and AT&T USB modems, and nearly three times faster than Sprint's fastest 4G WiMax modem.

The network

We knew the network was crazy-fast, nevertheless we were waiting to see whether the first LTE smartphones would reach the same high speeds. We predicted that they would, yet we were only half right: The ThunderBolt, even with the hardware limitations of a compact smartphone, in fact proved far faster than Verizon's LG 600 LTE modem in our tests.

Still, the ThunderBolt has been selling only since St. Patrick's Day, and Verizon's LTE modems have been on sale for less than four months. With the stunning 20-mbps-plus download speeds registering on the ThunderBolt, we can't help nevertheless wonder if the network is simply underutilized right now. Undoubtedly the LTE network was engineered to support millions and millions of users; when the load on the network comes closer to capacity, we might see download speeds settle down to the 5-to-12-mbps levels that Verizon has told users to expect.

The Samsung Galaxy S 4G is the first phone to support T-Mobile's new HSPA 21 network innovation, meaning that the handset is capable of reaching the 21 mbps of throughput speed that the T-Mobile network is built to deliver. This does not mean that the Galaxy S 4G should be expected to hit 21-mbps download speeds, however rather that it contains a radio and chipset capable of faster speeds than before T-Mobile phones achieved.

The Galaxy S 4G

The Galaxy S 4G was especially impressive in Las Vegas, registering download speeds of faster than 5 mbps at six of our ten testing locations there. In Los Angeles, the phone hit download speeds of more than 4 mbps in six of twelve locations, and averaged 3.23. The phone hit top speeds of 6.6 mbps in both San Francisco and San Jose.

Upload speeds were as well impressive. The Galaxy S 4G had upload speeds of more than 1 mbps in 27 of our 52 testing locations. Fast upload speeds are required for bidirectional applications just as online gaming and video chat. These apps as well depend on superfast network response time, and the Galaxy S 4G did very so then in that respect, too: Network latency times clocked in at less than 100 milliseconds in the vast majority of our testing locations. And the handset had an average latency score of just 103 milliseconds across our five testing cities.