If you want the best iPhone 7, you need to get the one with a Qualcomm modem.
According to a new study by Cellular Insights, the Qualcomm iPhone 7 and iPhone 7 Plus units—that's the Verizon, Sprint and factory-unlocked models—have more than 30 percent better performance in weak signal conditions than the AT&T and T-Mobile models, which have Intel modems.
Cellular Insights bought several iPhones at retail, and hooked them up to a box that simulates cellular networks to eliminate variables. We don't have that expensive equipment here. They tested the iPhones on LTE band 4—which is used by AT&T, T-Mobile, and Verizon—as well as band 12, which is used by AT&T and T-Mobile.
Both models of iPhone work equally well in strong signal conditions. We couldn't tell the difference with good signal, Cellular Insights couldn't, and you won't be able to, either. But when the signal weakened to about -105dBm—think of that as one bar of signal—the testers saw a major difference. At -110dBm on Band 4, the Qualcomm iPhone pushed 100Mbps while the Intel iPhone only reached 60Mbps, the report says.
"In all tests, the iPhone 7 Plus with the Qualcomm modem had a significant performance edge over the iPhone 7 Plus with the Intel modem," the report says.
There are some other shenanigans going on, too. Qualcomm's X12 modem supports a coding scheme called 256 QAM, which further speeds up LTE connections. That hasn't been activated on the iPhone 7, possibly to level the playing field with the Intel modem, which doesn't have the feature.
"Ironically, mobile operators such as T-Mobile USA and Telstra, which have been offering these advanced LTE features, are being supplied with the iPhone 7 with the Intel modem," the report says.
If this makes you ask the question of why Apple decided to go with an inferior Intel modem in the first place, you're not alone. Apple isn't saying. But as I've spoken to independent analysts, a picture became clear. Qualcomm is the leader in LTE, and Apple has been using their modems since the iPhone 4s generation. But Qualcomm tends to drive hard bargains. Intel hasn't had a big modem win with its XMM7360 devices before, so the company may have been an easier partner for Apple to deal with.
That said, for consumers, the choice is clear: if you care about getting the best connection with weak signal on your iPhone, it's worth grabbing one of those unlocked models from the Apple Store. They will have the superior Qualcomm modem.