According to Sina Finance, a teardown report found that the U.S. iPhone 18 Pro Max still uses Qualcomm's Snapdragon X80 chip rather than Apple's newly released in-house C2 chip.

TechInsights dissected the U.S. iPhone 18 Pro Max and found that its cellular communications system still uses Qualcomm's Snapdragon X80 chip. Apple's official specifications page also supported the finding, with the U.S. page listing the C2 chip only for the iPhone 18 Pro and not showing modem information for the Pro Max model.

By contrast, Pro and Pro Max models sold in Canada, the United Kingdom, and other overseas markets all come standard with Apple's in-house C2 chip. Industry analysts said Apple's C2 modem chip already supports 5G millimeter wave, offers better power efficiency than the previous C1 X chip, delivers faster upload speeds, and cuts power consumption by 15%.

The U.S. iPhone 18 Pro Max is the only model worldwide without the C2 chip, and the most likely reason is compliance with Apple's chip supply agreement signed with Qualcomm in 2023. As existing contracts gradually expire, Apple's shift to its in-house modem chips is expected to continue.