Apple’s iPhone Air, equipped with the C1X modem, delivers market-leading 5G performance without compromising on key metrics, according to benchmarks from networking firm Ookla.
Superior Latency Across Markets
Ookla tested the C1X modem in the iPhone Air against the Qualcomm X80 in the iPhone 17 Pro Max and Apple’s prior C1 chip in the iPhone 16e. The C1X excelled in latency, outperforming the X80 in 19 of 22 tested markets. These small but consistent advantages indicate Apple has rapidly matched Qualcomm’s established technology.
Ookla highlights that the C1X achieves “true download parity” with the X80 while setting “new standards for network latency.”
Download Speeds Hold Pace, Uploads Show Gains
Download speeds between the C1X and X80 remain closely matched. In the US, for instance, the X80 edges ahead in optimal conditions, but the C1X performs better in weak signal areas. Differences stay minimal overall.
Upload speeds favor the X80, with gaps up to 32% in some cases. However, the C1X marks a substantial improvement over the C1, delivering a “generational leap” in both downloads and latency.
Visible Upgrades for Everyday Use
Launched just one year after the C1, the C1X provides a “highly visible upgrade” over the iPhone 16e, especially for content sharing in most markets. Ookla concludes that Apple has created “the most responsive modem for daily use,” offering “no discernible sacrifice in peak 5G performance” compared to premium Pro models.
With Apple advancing its in-house modems—potentially including a C2 chip in the iPhone 18—competition intensifies. Qualcomm plans X85 modems for upcoming Android flagships, but Apple’s quick progress benefits users seeking reliable wireless connectivity.

