Potential iPhone owners, take note: Having the latest chips in your smartphone doesn't mean it's going to be the fastest phone possible.
As we wait for Apple to announce its upcoming iPhone X, we had Milan Milanovic, Ookla's Technical Evangelist, examine some of the top smartphones on the market sporting Qualcomm Snapdragon X16 gigabit LTE modems, the fastest modems available. As we saw in our Fastest Mobile Networks tests earlier this year, the modem in your phone really matters. While nobody's getting truly gigabit speeds from "gigabit LTE" phones in the real world, we've seen distinct differences in speeds and connectivity between phones supporting gigabit LTE technologies and phones that don't.
Gigabit LTE requires a bunch of technologies that have to be turned on both by the handset manufacturer and the wireless carrier. In the US, a phone needs to support at least three-channel carrier aggregation, which bonds together different slices of spectrum to make one broad highway. It needs four-branch antenna diversity and four physical antennas laid into the phone to support 4×4 MIMO, which boosts the capacity of a connection. And it needs 256QAM down and 64QAM up, advanced forms of encoding that can pack more bits into a radio pulse.
Milanovic has a key piece of equipment we don't have in-house. As well as their invaluable engineering support, Rohde & Schwarz also supplied CMWflexx test equipment consisting of two R&S CMW500s and one R&S CMWC controller, and a TS7124 RF Shielded Box equipped with four Vivaldi antennas for up to 4×4 MIMO, ensuring high reproducibility of OTA MIMO measurements.
Milanovic looked at four phones all packing the Qualcomm Snapdragon X16 modem, which supports Gigabit LTE. He found that while the Moto Z2 Force and Samsung Galaxy S8 run the table on gigabit technologies, the Essential PH-1 and Sony Xperia XZ Premium both fall short in the US for different reasons.
The Essential, it turns out, lacks the physical antennas to support 4×4 MIMO. Sony's sin is stranger: while it has all of the components for gigabit LTE, it only set them up for frequency bands that aren't used in the US. (bands 1, 3, and 7.) It looks like the US was just an afterthought for Sony's development team.
There are other upcoming gigabit LTE phones that we didn't include here. The LG V30 and Sony XZ1 aren't out yet. The Samsung Galaxy Note 8 has the same modem features as the S8, and we don't have an HTC U11 unit right now.
|Motorola Moto Z2 Force||Yes||Yes||Yes||Yes||Yes||1Gbps|
|Sony Xperia XZ Premium||Yes||Yes||No||No||No||450Mbps|
|Samsung Galaxy S8||Yes||Yes||Yes||Yes||Yes||1Gbps|
What This Means for the iPhone X
The iPhone X will likely use a mix of the Intel XMM 7480 modem and Qualcomm's X16 modem.
The 7480 supports 4-carrier aggregation and 256/64QAM, but not 4×4 MIMO. That restricts that modem to 600Mbps rather than gigabit speeds. It also lacks support for Verizon and Sprint's CDMA network. So Qualcomm's modem is likely to appear on Verizon and Sprint models, whereas Intel's modem will likely appear in other phones.
In the iPhone 7 generation, Apple turned off any features on Qualcomm's modem that were more advanced than Intel's so it could offer consistent performance across the iPhone lineup. (Even with those features turned off, the Qualcomm models showed superior performance, as Cellular Insights' analysis showed last year.)
It'll be very interesting to see what Apple chooses to do this year. We'll find out tomorrow at the iPhone announcement in Cupertino.