As soon as the iPhone 7 was released users began notice a difference in download speeds between the Verizon iPhone 7 which features a Qualcomm MDM9645M LTE modem and the AT&T version which has an Intel XMM7360 modem.
Cellular Insights performed tests which concluded that the average performance delta between the two is in the 30% range in favor of the Qualcomm variant.
Recently, Bloomberg reported on testing by Twin Prime which determined that although the Verizon model is faster than the Intel model, it still is not as fast as it could be. The Samsung Galaxy S7 which also uses the Qualcomm X12 was about twice as fast as the iPhone 7 running on the same network with the same modem chip.
“The data indicates that the iPhone 7 is not taking advantage of all of Verizon’s network capabilities,” said Gabriel Tavridis, head of product at Twin Prime. “I doubt that Apple is throttling each bit on the Verizon iPhone, but it could have chosen to not enable certain features of the network chip.”
Now, sources tell Re/code that it's true, Apple has limited the speed of the Qualcomm modem in the Verizon iPhone 7 to make it perform at about the same speed as the Intel modem.
Apple supposedly did this for a simple reason: It wanted the cost savings and flexibility of having two chip sources but also wanted the different versions of the phone to be as similar as possible (to avoid angering AT&T and T-Mobile and their customers in the U.S., for example).
Apple's official comment on the matter: “Every iPhone 7 and iPhone 7 Plus meets or exceeds all of Apple’s wireless performance standards, quality metrics, and reliability testing,” Apple spokeswoman Trudy Muller said. “In all of our rigorous lab tests based on wireless industry standards, in thousands of hours of real-world field testing, and in extensive carrier partner testing, the data shows there is no discernible difference in the wireless performance of any of the models."