Apple’s upcoming iPhone 17 Air might not be the speed demon you’re expecting, especially if you’re a T-Mobile customer. The ultra-thin phone is expected to use Apple’s own cellular modem instead of the Qualcomm chips that have powered iPhones for years, and new testing shows this could mean slower data speeds in some situations.

According to PhoneArena, network testing company Ookla has been comparing Apple’s new C1 modem (found in the iPhone 16e) with Qualcomm’s technology to see how they stack up. The results are mixed and largely depend on which wireless carrier you use.

T-Mobile users saw the biggest difference in download speeds. Phones with Qualcomm modems averaged 317 Mbps, while those with Apple’s C1 modem only hit 252 Mbps. That’s because T-Mobile’s network can combine up to four different frequency bands for faster speeds, but Apple’s modem can only handle three. It’s like having fewer lanes on a highway – there’s a bottleneck that limits how fast you can go.

The good news? Apple’s modem shines in areas where cell service is typically weak. If you live somewhere with spotty coverage or frequently find yourself in dead zones, the C1 modem actually performs better than Qualcomm’s chips. Apple seems to have prioritized reliability over raw speed, which could be more valuable for everyday users.

Battery life is another win for Apple’s approach. The C1 modem is more power-efficient than Qualcomm alternatives, which could help the razor-thin iPhone 17 Air last longer despite having a smaller battery due to its ultra-slim design.

For most people using Verizon or AT&T, the differences between Apple and Qualcomm modems are minimal. The real question is whether you value peak download speeds or consistent performance in challenging conditions. Apple’s betting that most users care more about having a working phone everywhere than squeezing out every last megabit per second.

The iPhone 17 Air is expected to be announced at Apple’s event, with the same modem technology that debuted in the more affordable iPhone 16e earlier this year.

Source: PhoneArena