The Apple C1X modem in the iPhone Air has achieved real-world download and latency performance on par with the Qualcomm X80, according to an analysis by Ookla using Speedtest Intelligence data from the fourth quarter of 2025.
Apple C1X Modem Performance vs. Qualcomm X80
Ookla’s data shows the Apple C1X modem led the previous C1 model in median download speeds across all markets studied. The improvement was most notable in the UAE, the United States, Saudi Arabia, China, Sweden, Singapore, and Japan. Furthermore, the C1X demonstrated significant gains over the C1 specifically on more advanced 5G networks.
iPhone Air Leads in Latency Across Most Markets
The iPhone Air outperformed the Qualcomm-based iPhone 17 Pro Max in latency metrics across 19 of 22 analyzed markets. Latency performance is a key indicator of network responsiveness for applications such as video calls and online gaming.
Strong Results in Saudi Arabia and the UAE
In the UAE, the iPhone Air delivered a 643.9 Mbps download speed advantage over the iPhone 16e, recording 1,832.3 Mbps compared to 1,188.4 Mbps. Ookla noted the UAE holds the position of the fastest 5G market in the world. In Saudi Arabia, the iPhone Air provided 362.8 Mbps more bandwidth, recording 970.0 Mbps versus 607.2 Mbps on the iPhone 16e.
“The C1X shows significant upside vs. the C1 in more advanced 5G networks, including the UAE and Saudi Arabia.”
Ookla, Speedtest Intelligence Report, Q4 2025
Qualcomm Retains Upload Speed Advantage
Despite the gains in download performance, the Qualcomm X80-equipped iPhone 17 Pro Max maintained up to a 32% lead in upload speeds. Ookla stated that Qualcomm’s mature implementation of Uplink Carrier Aggregation (UL-CA) remains the benchmark in that category. Apple has achieved parity in download metrics, but the upload gap represents an area where further development is needed.
Context and Outlook
The C1X is Apple’s second in-house modem chip, following the C1 introduced earlier. The analysis covers performance data across 22 global markets. Moreover, the results suggest Apple is closing the gap with Qualcomm in core cellular connectivity metrics, though upload performance remains a differentiator for Qualcomm-equipped devices. Continued modem development from Apple could further shift the competitive landscape in future iPhone generations.