With the iPhone 7 and iPhone 7 Plus, Apple chose to source cellular modems from two companies after relying solely on Qualcomm for years. The A1660 and A1661 models of the latest iPhones feature Qualcomm modems while the A1778 and A1784 versions come with Intel modems. Intel had been trying to get its chips inside the iPhones for years.

iPhone 7 Plus
Image Credit: Apple Inc.

30% performance gap between two versions of iPhone 7 Plus

Folks at Cellular Insights tested the difference between the Intel- and Qualcomm-powered iPhone 7 Plus. They found that the Qualcomm version was way ahead of the Intel one where LTE signal was poor. Both variants work just fine when there is good LTE connectivity. But there is about 30% gap between the two versions of the iPhone 7 Plus when the signal is fainter.

iPhone 7 Plus Intel Modem
Image Credit: Cellular Insights

That’s not all. The Intel-powered iPhone 7 Plus lags behind many other devices such as the iPhone 6S, Google Nexus 5X, and LG G5. It’s worth pointing out that neither versions of the iPhone 7 Plus came even close to Samsung’s Galaxy S7 Edge, which topped the charts. Cellular Insights initially thought the Intel-powered iPhone was defective, so they bought a new one. But the results were identical.

iphone-7-plus-qualcomm
Image Credit: Cellular Insights

Qualcomm’s modem supports EVS; Intel doesn’t

Intel’s cellular modem only supports GSM-based networks, while Qualcomm modems are compatible with both GSM and CDMA networks. That’s why Apple has made the Intel-powered iPhones available only for AT&T and T-Mobile. SIM-unlocked, Verizon, and Sprint models feature Qualcomm modems. Check out Cellular Insights’ test page for the details on hardware and testing methods.

Cellular Insights also pointed out that Qualcomm’s modem has the ability to take advantage of Ultra HD Voice. However, Apple seems to have disabled it to level the playing field with the Intel-powered iPhones. Ultra HD Voice or the Enhanced Voice Service (EVS) results in much better audio quality, and higher-fidelity calls than HD Voice. At this point, only T-Mobile has deployed Ultra HD Voice on its network, and T-Mobile customers get the Intel version of iPhone 7 and 7 Plus, which does not support EVS.

Supply chain diversification leads to performance difference

Apple probably chose to source cellular modems from two companies this year to broaden its supplier base. Having multiple suppliers could mean pricing competition. Though the diversification has led to a performance difference between the two variants in controlled environments, it is unclear how their performance would differ in real world.

This is not the first time two different versions of the iPhone 7 and 7 Plus have been found to have performance differences. Earlier this month, tests conducted by GSM Arena revealed that the 32GB iPhones have a much lower storage performance than the 128GB and 256GB versions.