A First Look at How Apple’s C1 Modem Performs With Early Adopters – Ookla

The 16e is the first iPhone to feature the Apple-designed C1 modem.

Key Takeaways:

• AT&T and Verizon Speedtest® users experienced better median download speeds on the iPhone 16e than iPhone 16. However, the opposite was true for T-Mobile users. 

• Verizon Speedtest users with the iPhone 16e and the iPhone 16 experienced median download speeds that lagged behind that of both AT&T and T-Mobile. 
• iPhone 16e Speedtest users on Verizon’s network and AT&T’s network saw higher upload speed performance than those using the iPhone 16. However, T-Mobile users experienced the opposite and had slightly higher upload speeds on the iPhone 16 compared to the iPhone 16e.

Apple’s new iPhone 16e made its commercial debut in late February with much fanfare because it’s the first device to include the Apple-designed C1 modem. Historically, Apple relied upon Qualcomm to provide most of its iPhone modems so its decision to use the C1 modem in the iPhone 16e is considered a significant move.  

Although it’s early in the adoption curve for the iPhone 16e, we analyzed the performance of the new device from March 1st through March 12th, and compared it to the performance of iPhone 16, which has a similar design and the same 6.1” screen. Both devices run on the same Apple-designed A18 SoC. However, it’s important to note that unlike the iPhone 16, the iPhone 16e does not support mmWave spectrum. This is the first iPhone available in the U.S. without mmWave support but we expect future iterations of the C1 modem will include it. 

iPhone 16 offers higher top-end performance than the iPhone 16e 

When we compare Speedtest Intelligence® data from the top 90th percentile (those with the highest performance experience) of iPhone 16e and iPhone 16 users  from all three of the top U.S. operators, we see the iPhone 16 performing better in download speeds. However, at the opposite end, with the 10th percentile of users (those who experience the lowest performance) we see the iPhone 16e performing better than the iPhone 16. 

iPhone 16e outperforms on download speeds for AT&T and Verizon, but not T-Mobile

Speedtest data shows the iPhone16e recorded faster median download speeds than the iPhone 16 on both AT&T and Verizon’s networks, but was markedly slower on T-Mobile’s network. 

iPhone 16e users on T-Mobile’s network experienced median download speeds of 264.71 Mbps, which is at least 47% faster than iPhone 16e users on Verizon’s network that experienced median download speeds of 140.77 Mbps. The download speed performance for iPhone 16e users on AT&T’s network was 226.90 Mbps, closer to that of T-Mobile users. 

However, when comparing median download speeds for T-Mobile users with the iPhone 16e (264.71 Mbps) to T-Mobile users with the iPhone 16 device (357.47 Mbps), the iPhone 16 outperformed the iPhone 16e by at least 24%.

The iPhone 16e’s underperformance in median download speed compared to the iPhone 16 on T-Mobile’s network is most likely due to the fact that T-Mobile is the only US carrier to have a nationwide commercialized 5G standalone network (SA) and one of the few operators globally to deploy significant spectrum depth and advanced features like carrier aggregation (CA) on the new 5G architecture. 

The C1 modem’s more limited capabilities on 5G SA networks compared to the Qualcomm modem in the iPhone 16 may be a key factor contributing to the larger performance gap between device models observed on T-Mobile’s network in early testing.

Verizon’s download performance lags on both devices

While much has been made of the lack of mmWave support on the iPhone 16e, which will have some impact on performance, particularly for users that are in range of these higher bands, both Verizon Speedtest users with the iPhone 16e and the iPhone 16 experienced median download speeds that lagged behind that of both AT&T and T-Mobile.

iPhone 16e beats the 16 among those in the 10th percentile

When we examine Speedtest Intelligence® data for the bottom 10th percentile  (those with the lowest overall download speeds) of iPhone 16e vs. iPhone 16 users, we see that iPhone 16e users experienced better download speeds compared to iPhone 16 users across all three mobile providers.  

For example, T-Mobile iPhone 16e users in the bottom 10th percentile are experiencing speeds of 57.34 Mbps compared to T-Mobile iPhone 16 users that are experiencing speeds of just  27.27 Mbps.

At the other end of the scale at the 90th percentile (those with the fastest overall download speeds), we saw the reverse with the iPhone 16 outpacing the iPhone 16e for each mobile provider. For example, T-Mobile iPhone 16 users in the 90th percentile experienced blazing fast median download speeds of 889.83 Mbps compared to T-Mobile iPhone 16e users that are experiencing median download speeds of 627.01 Mbps.

Performance at the lowest 10th percentile often provides a more accurate reflection of overall quality of experience (QoE) than the fastest 90th percentile, which can be skewed by deployments in mmWave-covered locations and is subject to declining marginal returns.

iPhone 16e is higher in upload speeds

Interestingly, in upload speeds, we saw iPhone 16e users on Verizon and AT&T experiencing higher upload speed performance than those using the iPhone 16. T-Mobile users, however, experienced just slightly higher upload speeds on the iPhone 16e compared to the iPhone 16. The gap was the biggest with AT&T iPhone 16e customers, who experienced median upload speeds of 14.63 Mbps, which is at least a 38% increase over AT&T iPhone 16 users who experienced median upload speeds of 8.60 Mbps. 

Apple’s departure from Qualcomm

Apple has historically sourced its iPhone modems from Qualcomm but in 2019 the company purchased Intel’s modem business with the goal of designing its own in-house modems. 

Apple’s iPhone 16e with the C1 modem supports all the low and mid-band 5G spectrum but, as mentioned above, it doesn’t support mmWave spectrum. It also supports Wi-Fi 6 with 2×2 MIMO and Bluetooth 5.3, but lacks Wi-Fi 7 support unlike the rest of the iPhone 16 series of devices. 

Apple claims that the C1 is more power-efficient than any modem ever used in an iPhone and said that the 16e has a new internal design, which allows it to give the device a bigger battery.  In its 16e specifications Apple claims that the 16e has a battery life of up to 26 hours with video playback and up to 21 hours with streaming video playback. This compares to the Apple 16 which Apple claims has a battery life of up to 22 hours with video playback and up to 18 hours with streaming video playback. 

Some of the performance differences that Speedtest data picked up between the iPhone 16e and the iPhone 16 may also be attributed to the fact that the C1 modem doesn’t have all the same capabilities that are featured in Qualcomm’s modems. 

According to a Qualcomm comparison of the C1 and its mid-tier and premium modems, Qualcomm’s mid-tier modems support 4CA downlink carrier aggregation and its top of the line x80 and x85 modems support 6CA downlink carrier aggregation compared to the C1 which supports just 3x downlink carrier aggregation. Qualcomm’s mid-tier, x80 and x85 modems also support uplink carrier aggregation and uplink MIMO and the Apple C1 does not. 

We will continue to monitor the performance of the iPhone 16e as adoption of the device increases around the world and we plan to publish a more comprehensive comparison across the entire iPhone 16 portfolio of devices. While we have not analyzed the iPhone 16 Pro Max’s performance here because it is in the premium device category, we do see it leading over the iPhone 16e in most performance metrics. 

Ookla analysts Mark Giles, Luke Kehoe and Kerry Baker contributed to this piece. 

To find out more about Speedtest Intelligence® data and insights, please contact us here.

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About the Author

Sue Marek

Sue Marek is Ookla’s editorial director and part of the company’s analyst team. She oversees the company’s thought leadership and editorial content. Sue is a journalist with more than 30 years of experience covering the telecom industry and her work has appeared in Fierce Network, Light Reading, and SDxCentral. She is a frequent speaker at industry events and has moderated panels at Mobile World Las Vegas, Connect(x), the Consumer Electronics Show, the Competitive Carriers’ Show and 5G North America. Sue has a B.S. in journalism from the University of Colorado.