Apple C1 modem real-world tests: Good enough, but a step slow

In many ways, the Apple C1—its first cellular modem—is the company’s most important product in years. Just as the company broke free from reliance on Intel with its own Mac processors, it is now breaking free from reliance on Qualcomm for cellular connectivity. Ditching Broadcom for its own Wi-Fi and Bluetooth is said to happen this year, too.

But the chip was released to little fanfare, with the announcement all but buried in the details of the iPhone 16e. After testing the modem, we know why: it’s good enough for Apple’s “budget” iPhone 16e, but only just.

We carried the iPhone 16 and iPhone 16e all over Sacramento, Calif., taking multiple speed tests to compare Apple’s modem vs. Qualcomm’s. The results are clear: Apple can’t keep up, at least not yet. But speed is not all that matters to a cellular modem.

Apple C1 modem: How we tested

To thoroughly test a cellular modem requires taking thousands of measurements all over the world, when connected to various networks in different conditions, in addition to controlled lab conditions. We can’t do all of that, but we can schlep around an iPhone 16 and iPhone 16e, taking multiple measurements in multiple locations, until we get enough data to form some conclusions.

We used the popular Ookla Speedtest app to test network performance. Since performance is so highly variable, we took three measurements in each location on each phone, one after the other, and averaged the results.

Our tests were performed on the Verizon network at multiple locations throughout the Sacramento, CA area, primarily in the afternoon on a day with good weather. We tested indoors and outdoors, in a mix of challenging areas, such as within a grocery store or the locker room of a gym, and easy, high-performance areas such as outside the Golden 1 Center when there was no major event taking place.

The C1 does not support mmWave, so we don’t expect multi-gigabit speeds, but even more important than occasional Wi-Fi speeds is how well it performs in areas where the connection is weak or saturated. Let’s see how the C1 holds up.

Apple C1 modem: Downloads and uploads

With the exception of the test run in my home office (which has poor connectivity with mobile networks), the Qualcomm X71M in the iPhone 16 raced past the Apple C1 in every location. In the supermarket where it’s hard to get a really good connection, the C1 bombed hard, downloading at only about 10 megabits/s while the Qualcomm modem managed over 200. Remember, this is the average of three successive tests, to reduce the natural variability of cellular performance.

It’s possible the iPhone 16e wasn’t able to lock on to a signal on a band that performs better there, but regardless of the reason, through multiple tests, we simply couldn’t get a good connection.

In the park or Golden 1 Center where the iPhone 16 gets over a gigabit of download speed, we’re not very concerned by the Apple C1 managing half the performance. Once you can download several hundred megabits per second, you’re not going to have a very different experience going faster—not on your smartphone.

Upload performance was a lot closer, with the Apple C1 trading wins with the Snapdragon X71M.

If there’s a problem, it’s with the tests taken inside the gym or out in the nearby shopping center, where the Qualcomm modem was several times faster than Apple’s. The gym in particular is a very challenging area; it’s indoors in a large building full of equipment where connectivity is spotty, and dozens of people are all on their phones at once while they work out. We couldn’t even get half a megabit of upload performance out of the iPhone 16e there.

Apple C1 modem: Overall performance

Taking the speeds from each location and averaging them together, we start to see a general overall picture of how the Apple C1 modem in the iPhone 16e compares to the Qualcomm Snapdragon X71M in the iPhone 16.

You can say that, at least in our testing in a variety of locations, the Apple C1 delivers about the same overall upload speed as the Qualcomm Snapdragon X71M but about half the download performance.

Again, that’s all highly dependent on location and conditions, but it was consistent enough to show a clear pattern.

Apple C1 modem: Efficiency and reliability

Of course, download and upload speeds are only part of the picture when it comes to cellular performance. It’s just as important that you don’t drop calls, and that this very power-hungry component doesn’t drain your battery too quickly.

We made several spot calls during testing using both phones and noticed no significant difference in call quality. No call ever dropped on either phone. It would take hundreds of calls in lots of locations, all lasting ten minutes or more, to get a really clear picture of whether one modem drops calls more than the other, so consider our tests anecdotal at best.

Power efficiency testing also requires some specialized equipment to isolate the power draw of the modem alone, and measure it with different signal strengths. That’s exactly what Chinese YouTuber 极客湾Geekerwan has done, and they found that indeed, under ideal conditions, the Apple C1 uses about 25 percent less power than the Snapdragon X71M in the iPhone 16, but that power savings grows smaller if the signal is weak.

We’re talking about a difference of one-fifth of a watt, which can add up over time, but it’s not really a massive contributor to overall battery life. The iPhone 16e has a higher-capacity battery than any 6.1-inch iPhone before; it holds about 12% more charge than the battery in the iPhone 16, and that seems to be the biggest factor in the iPhone 16e’s long battery life.

The C1 is not good enough for flagship iPhones… yet

The iPhone 16e is Apple’s “more affordable” iPhone, though at $600 or more it could hardly be considered a budget smartphone. It makes several concessions to shave $200 off the price, and we can consider cellular performance to be one of them.

Making a competitive 5G modem is a herculean task, one that was beyond Intel’s reach (and hence why the company sold its whole modem division to Apple). There’s a reason Apple is years late in bringing a modem to market. That it works and seems to work just fine without any massive obvious flaws, is quite a feat in itself.

But it can’t keep up with Qualcomm’s Snapdragon X71M in the iPhone 16, and that’s not even Qualcomm’s best modem, which would be the Snapdragon x80. It’s not even the X75, which was found in a lot of phones last year. It appears to be some sort of custom-made-for-Apple variant on the X70, though details are scarce.

The Apple C1 is good enough for the company’s less expensive model, but if you’re spending $800+ on the latest iPhone, or $1,000+ on an iPhone Pro, you expect better than “good enough.” Without obvious evidence that it drastically improves battery life, which we don’t see, it would be a huge disappointment to find the C1 in the iPhone 17 this fall. Thankfully, rumors claim that Apple will indeed stick with Qualcomm for at least another generation.

But Apple says this is the first modem of many. The company already has C2 and C3 modems in the pipeline (it would have to, considering the multi-year development and testing process). Those are supposed to get closer to the performance of Qualcomm’s best modems while improving power efficiency and offering tighter integration with other Apple silicon. The C1 is a great start but Apple still has a long way to go.