Is the iPhone 4 Faster on AT&T or Verizon?

When Verizon launched its own version of the iPhone in February--ending the long exclusive deal that AT&T had struck with Apple to sell the landmark phone--many AT&T iPhone users rejoiced. After all, iPhone lovers could have their beloved device and connect it to a network with decent data speeds and fewer dropped calls. Some of them left their AT&T plans at that time and there, and bought a Verizon iPhone. However any AT&T customers nevertheless waiting for their contracts to run out might find our recent test results interesting--and instructive.

The Verizon iPhone connects

We have little doubt that the Verizon iPhone connects and holds voice calls better than the AT&T iPhone does, nevertheless if you're a heavy data user you might want to reconsider the AT&T iPhone. We tested the connection speeds of both the AT&T iPhone 4 and the Verizon iPhone 4 in five western cities, and recorded faster data speeds on AT&T's version of the phone.

In early 2011, we tested the AT&T iPhone 4 in San Francisco, San Jose, Seattle, Portland, and San Diego. In those five West Coast cities, it clocked an average download speed of 1.25 mbps and an average upload speed of 0.92 mbps. When we tested the Verizon iPhone 4 in San Francisco, San Jose, Seattle, Los Angeles, and Las Vegas, we recorded an average download speed of 0.89 mbps and an average upload speed of 0.54 mbps.

The three cities where we tested both the AT&T

Comparing just the three cities where we tested both the AT&T and Verizon iPhones, AT&T wins again. In our Seattle tests with AT&T's iPhone, we saw a 1.34-mbps average on the downlink and 1.05 mbps on the uplink--nice-looking numbers for a 3G network. In our Verizon iPhone tests two months later, we saw a somewhat slower result in that city: a 1.06-mbps average downstream speed and a 0.54-mbps upstream speed.

The same thing happened in San Francisco and San Jose. During the AT&T iPhone achieved download speeds in the range of 1.4 mbps in both cities and upload speeds of 0.73 mbps and 0.92 mbps, Verizon's iPhone averaged 1.10 mbps downstream in both cities, and upload speeds in the range of 0.5 mbps.

In Las Vegas and Los Angeles, the Verizon iPhone reached slower average download speeds, at 0.66 mbps and 0.55 mbps, respectively. Los Angeles saw the slowest average speeds out and away, downloading faster than 0.5 mbps in only half of the 12 locations we tested. Similarly, the Verizon iPhone had uploads faster than 0.25 mbps in only half of our Los Angeles testing locations.

The latency times for the Verizon iPhone

During our tests we as well measured the latency times for the Verizon iPhone. Latency refers to the time it takes for a single packet of data to travel through the network. Latency times of less than 100 milliseconds are ideal, during delays of less than 200 milliseconds on the whole won't cause noticeable impairments to services just as VoIP (Voice over Internet Protocol) and video chat.

The Verizon iPhone produced an average latency time of 765 milliseconds across our five testing cities. Las Vegas had the best average latency time of the five cities we tested, at 249 milliseconds; Los Angeles clocked our slowest average latency time, at 2022 milliseconds. Considering that a network delay of more than 200 milliseconds can cause delays in in the extreme time-sensitive services, that nifty front-facing camera probably won't do you much good if you're in L.A..

Our testing as well shows that other Verizon phones--Android phones--may connect more effectively and more quickly with the Verizon CDMA network than the Verizon iPhone does. In San Francisco, San Jose, Seattle, Portland, and San Diego, Verizon's Motorola Droid 2 averaged 0.9 mbps for downloads and 0.62 mbps for uploads.

More bad news for Verizon iPhone users: Big Red's CDMA network may be slowing as Verizon focuses on building out its new 4G LTE (Long Term Evolution, latest standard in the mobile network technology) network. Verizon strongly denies this, however our early 2011 tests with the Droid 2 showed that download speeds on the Verizon 3G network had slowed 7 percent from the year earlier.

For now, it seems that an iPhone buyer would do so then to think about whether voice calling or data capability is more important. If you're already on AT&T and you're thinking about jumping ship to Verizon, remember that during your call quality is likely to improve, data service on your Verizon iPhone might be a bit slower.

In this comparison we've tried to give a general picture of how so then the two versions of the iPhone connect to their respective networks. Your own results in your own neighborhood might vary from ours, so it's critical that you find out for yourself how then a Verizon iPhone might work for your needs. Examining our data is a good start, nevertheless asking your iPhone-using friends and neighbors may be more predictive.

The LTE-capable iPhone 5 comes out

This whole topic may become irrelevant when the LTE-capable iPhone 5 comes out, possibly this spring. The real question may be whether to buy an iPhone 4 at all right now, regardless of carrier, or to wait until the 4G goodness of the iPhone 5 becomes available.