In an effort to offer a uniform experience on the iPhone 7 regardless of carrier, Apple could be reducing the top speeds capable on Verizon, keeping them on par with rival carrier AT&T, a new investigation alleges.

Apple's choice of LTE modem suppliers for the new iPhone 7 series is believed to be the main cause for the issue, according to Bloomberg. Specifically, the Intel modem featured in AT&T-compatible iPhone 7 units offers slower download speeds than the Qualcomm modem found in Verizon units.

Apple for years has diversified its supply chain to help keep production levels high and also drive down costs. A similar controversy erupted last year, when it was discovered that A9 processors in the iPhone 6s were made by both Samsung and Taiwan Semiconductor Manufacturing Co.

While some benchmark tests suggested not all A9 chips were created equal, Apple said that in real-world use, the processors performed similarly. Tests subsequently confirmed those claims.

While variations in performance are to be expected from multiple suppliers, the difference between the Qualcomm and Intel modems is said to be far more pronounced: Qualcomm's X12 modem is capable of up to 600 megabits per second, while Intel's maximum speed is just 450 megabits per second.

Tests conducted by Twin Prime found that the Verizon iPhone 7 offers slightly faster LTE speeds than AT&T. But the same Qualcomm X12 chip is found in the Samsung Galaxy S7, and its network speeds on Verizon are about twice as fast as the iPhone 7.

The suggestion is that Apple is throttling the performance of the X12 modem in the Verizon iPhone 7 so that it matches the capabilities of Intel's modem in the AT&T version.