iPhone X

Qualcomm-powered iPhone X models get consistently better LTE speeds than Intel's on America's most common LTE band, according to new test results from Cellular Insights.

While Apple's iPhone 4s through 6s units all used modems from Qualcomm, last year the company decided to split its business between Qualcomm and Intel, resulting in two iPhone 7 units with very different LTE performance. Since then, Apple has become Intel's largest smartphone modem customer by far. This year, Apple doubled down, continuing the Qualcomm-Intel split.

There are three iPhone X models sold globally. Using lab equipment, Cellular Insights tested two of them: the Qualcomm-powered A1865, sold by Sprint, Verizon, and U.S. Cellular and in Australia, China, and India; and the Intel-powered A1901, sold by most other global carriers including AT&T and T-Mobile. (The third model, A1902, is only sold in Japan.) Here in the US, we anticipate that the SIM-free model sold directly by Apple will be the A1865, as that's the model that supports all four US carriers.
For this test, Cellular Insights looked at performance on LTE Band 4, which is used by every major US carrier except Sprint, as well as in Canada and parts of Latin America.
iPhone X speed chart

Cellular Insights attenuated an LTE signal from a strong -85dBm until the modems showed no performance. While both modems started out with 195Mbps of download throughput on a 20MHz carrier, the Qualcomm difference appeared quickly, as the Intel modem dropped to 169Mbps at -87dBm. The Qualcomm modem took an additional -6dBm of attenuation to get to that speed.
Most consumers will feel the difference in very weak signal conditions, where every dBm of signal matters, so we zoomed in on that in the chart below. At very weak signal strength, below -120dBm, the Qualcomm modem got speeds on average 67 percent faster than the Intel modem. The Intel modem finally died at -129dBm and the Qualcomm modem died at -130dBm, so we didn't find a lot of difference in when the modems finally gave out.
iPhone X - weak signal
The iPhone 8 and 8 Plus have the same division of modems, although we did not test those models specifically.

Rohde & Schwarz, the global leader in test and measurement equipment, provided Cellular Insights with the cutting-edge CMWFlexx solution (shown below) consisting of two CMW500 Wideband Communication Tester boxes, CMWC Controller, and R&S TS7124 RF shielded box equipped with four Vivaldi antennas for up to 4×4 MIMO, ensuring high reproducibility of near-field OTA MIMO measurements. The study was done independently by Cellular Insights and shared with PCMag.
Rhode & Schwarz Unit
The two iPhone X units were running iOS 11.1.2. Cellular Insights' methodology was the same as last year's, which you can read in its 2016 report.
Compared to last year's tests, while Intel's modem hasn't caught up to Qualcomm's, there's a considerably smaller difference between the two. Below, we've copied the Cellular Insights chart for last year's iPhone 7 Plus tests: you can see that the Intel iPhone 7 Plus modem drops off a cliff between -105 and -110dBm, while it tracks a little below the Qualcomm modem's performance much more closely this year. This year's Intel modem is also able to squeeze out some performance at -129dBm, as opposed to the -125dBm of last year's device.
iPhone 7 Speed Chart
We wonder if Apple is specifically tuning the phones to have similar performance, though, because of the difference between 2017 and 2016 Qualcomm results. While the peak and weak-signal performance of this year's Qualcomm modem were both better than last year's, the speeds Cellular Insights saw on Qualcomm's modem between -97 and -117dBm were actually lower than last year's, and much closer to those of this year's Intel modem. Apple may be trying to make sure that T-Mobile and AT&T don't become jealous of Sprint and Verizon.

Crippled Features

Both the Qualcomm and Intel iPhones use the companies' latest retail modems as of September 2017. The Qualcomm model uses the X16, which is also in the Samsung Galaxy S8, LG V30, Google Pixel 2, Essential PH-1 and other flagship phones. The Intel model uses the Intel XMM7480.

The Qualcomm X16 modem in the iPhone X supports 4x4 MIMO antennas, 4-way carrier aggregation, and LAA, all of which can be bundled together in various ways to make "gigabit LTE" networks. All four US carriers currently say they're doing gigabit LTE using 4x4 MIMO and 3-way carrier aggregation.

However, those features are disabled in the new iPhones, possibly because the Intel modem doesn't support 4x4 MIMO or LAA, and Apple wants a level playing field. That makes both models of the iPhone X "600Mbps" rather than "gigabit" phones. There's one exception: in Australia, the Qualcomm modem is capable of 80MHz, four-way carrier aggregation on bands 1+3+7+28, and thus "800Mbps" speeds. A similar four-way combination (2+4+7+7) could have benefitted Canadian carriers where they have 75MHz of spectrum deployed, but the iPhone does not support that band combination.

The iPhone 8/X modems get a maximum of 200Mbps per 20MHz channel, as opposed to 150Mbps on the iPhone 7 models. The iPhone 8/X modems are able to net higher speeds using the same 20MHz channels because of their support for 256QAM encoding, which packs more data into each transmission symbol. The iPhone 7's Qualcomm X12 modem supported 256QAM, but Apple left it turned off, possibly because Intel's XMM7360 didn't have 256QAM support. The XMM7480 does, so Apple is turning the X16's 256QAM support on.

The End of Qualcomm?

The iPhone X may be Qualcomm's last hurrah with Apple, though. Qualcomm and Apple are locked in a web of lawsuits basically centering on Apple not wanting to pay the license fees that Qualcomm wants to charge.
Until now, Apple has been stuck with Qualcomm modems because it's the only provider offering high-end modems that work on the Sprint and Verizon CDMA networks. Intel's XMM7560 modem, which is supposedly coming to market next year, will support CDMA and thus Apple won't have any need for Qualcomm.
Further down the road, Apple may cast off Intel as well. The company recently hired a Qualcomm executive and is rumored to be working on a project to develop its own modems, which might result in a product in 2019 or 2020.
For now, though, getting an iPhone with the Qualcomm modem is still the way to go if you want the best possible LTE performance. You can do that by purchasing the factory-unlocked, SIM-free model directly from Apple in the US or Australia, or by purchasing a Verizon Wireless or Sprint unit. Sprint units come locked to Sprint, but Verizon units are unlocked.


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