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iPhone 7 Plus Qualcomm LTE Modem Significantly Outperforms Intel LTE Modem, Study Finds (macrumors.com)
An anonymous reader quotes a report from Mac Rumors: With the iPhone 7 and the iPhone 7 Plus, Apple elected to use LTE modems from two different sources, Qualcomm and Intel. The A1778 and A1784 iPhone models use a GSM-only Intel XMM7360 modem while the A1660 and 1661 iPhone models use a GSM/CDMA-compatible Qualcomm MDM9645M modem. Apple's decision has already caused some disappointment among customers because the GSM-only Intel modem is not compatible with as many carrier networks as the GSM/CDMA Qualcomm modem, and now independent testing conducted by Cellular Insights suggests there are some significant performance differences between the two modems, with the Qualcomm modem outperforming the Intel modem. Using an RS TS7124 RF Shielded Box, two RS CMW500, one RS CMWC controller, and four Vivaldi antennas, Cellular Insights created a setup to simulate LTE performance at different distances from a cellular tower using two iPhone 7 Plus devices, one with an Intel modem and one with a Qualcomm modem. The goal of the test was to measure the highest achievable LTE throughput starting at a Reference Signal Received Quality of -85dBm (a strong signal) and gradually reducing the power level to simulate moving away from a cellular tower where signal is weaker. Three LTE bands were tested: Band 12, Band 4 (the most common band in North America), and Band 7. In all three tests, both the iPhone 7 Plus models offered similar performance in ideal conditions, but as power levels decreased, Cellular Insights saw "unexplainable sharp dips in performance" in the Intel modem, finding a gap "north of 30%" in favor of the Qualcomm iPhone 7 Plus. In the charts, the Qualcomm modem maintains noticeably higher throughput speeds than the Intel modem as signal strength decreases. According to Cellular Insights, in every single test, the iPhone 7 Plus with a Qualcomm modem "had a significant performance edge" over the iPhone 7 Plus with an Intel modem.
It looks like Intel is still playing catch up in the modem space. Interestingly, it looks like for the 2016 iPhone, Apple is using either the Intel XMM 7360 or the Qualcomm X12. Both of these modems were released in 2015. Qualcomm hasn't shipped a new generation since then, but Intel did release the XMM 7480 in February. It would be interesting to see how much progress Intel has made in a year.
Either way, the fact that Intel's modem exists is good for everyone... except Qualcomm. Without it, Qualcomm would be the only LTE modem supplier. There is no doubt Apple is aware of the Intel modem's shortcomings. My guess is Apple is willing to turn a blind eye to that for the "1st gen" product and use the new revenue as a carrot to get Intel to direct its engineering efforts to the features that Apple wants, probably stuff like CDMA for example.
Not only did Apple know, but there were public discussions about it the very same day that they announced the iPhone 7. I don't have the links in front of me, but some people on Reddit did a very technical overview of the differences between the two modems. the TL;DR version of the story (assuming my memory serves me correctly) is that the Qualcomm chip can handle 4 LTE bands at once and the Intel only two or some such thing. To my knowledge, no cellular network provides speeds that the Qualcomm version of the iPhone 7 can take advantage of that the Intel version cannot. Not to say that will change, but this test is all theoretical anyway. It's lab based.