With a starting price tag of $649, millions of people have bought Apple’s new iPhone 7, as well as the more expensive iPhone 7 Plus, since the phones made their debut in September. 

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Do you have the ‘slower’ version of the iPhone 7?

But according to CNN, some iPhone 7s use a Qualcomm modem and others have an Intel modem, which could affect how quickly your device works. Recent testing of the iPhone 7 Plus by Cellular Insights found that the Qualcomm modem performed 30% better. 

BGR.com reports that iPhone users likely won’t notice a big difference when there’s a strong LTE signal, but the slowness may be apparent in areas of poor coverage.

How do you make sure you get the faster modem? In the United States, Verizon, Sprint and SIM unlocked iPhone 7 and iPhone 7 Plus models have the Qualcomm modem. AT&T and T-Mobile devices are equipped with the Intel modem.

According to Forbes, you can also check the model number listed on the back of your phone. Model A1660 and Model A1661 have a Qualcomm modem, and Model A1778 and Model A1784 come with an Intel modem.

Despite the difference with the modems, the Cellular Insights report described the iPhone 7 Plus as a “beautifully designed smartphone” with “arguably the best-in-class camera and system performance.”

It’s not clear why Apple decided to use two different types of modems for the new phones. 

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