Apple specifically restricted the speed of the modem of Qualcomm in some smartphones your iPhone to compare the results with the modem Intel
After the release of the new Apple smartphones on the market, the Network began to receive complaints about the speed of modem Intel in certain versions of new products. Such supposedly much inferior Qualcomm. If you search in the web you can find tests that show quite the opposite, but to a greater extent users abused it modems Intel.
Then Apple said that all devices provide the same experience regardless of manufacturer components. According to the source, this is the «same experience» is actually reached due to incomplete, in a sense, the operation of modems Qualcomm.
Experts came to the conclusion that Apple had to limit the ability of new Qualcomm modems X12, so they do not stand out against Intel. How much faster could work modems Qualcomm in the absence of limitations is unclear. But you can learn about, compare with the capabilities of the Samsung Galaxy S7 smartphone equipped with SoC Snapdragon 820 with the same modem. The advantage of the latter can reach 20-25%.
Conclusion based on the analysis of the speed of loading the images more than 100,000 smartphones in different cities of the United States.
Note that us operators Verizon and Sprint sell iPhone with modems, Qualcomm, and AT&T and T-Mobile — modems Intel.