Qualcomm baseband is good, the main difference lies in download speed and signal strength.
Download speed Even though Apple has made significant adjustments and optimizations to the two basebands in order to balance the user experience, the download speed of Qualcomm X16 is stronger than that of Intel XMM7480 under different signal strengths. In an environment with extremely weak signals, Qualcomm baseband performs better. In a -129db environment, the Intel baseband version can no longer receive signals at all, while the Qualcomm version still has weak download capabilities. However, the performance gap compared to the iPhone 7 has been significantly narrowed, which shows that Apple has been more attentive to "optimization".
The baseband is similar to Modena in our computers. Phone calls, text messages, traffic, etc. in mobile phones are all realized through the baseband. The function of the baseband determines our communication method, using 2G, 3G or 4G network; completing the demodulation and decoding of wireless network signals, and transmitting the decoded digital signals to the upper-layer system for processing; the digital signal instructions issued by the upper-layer system , modulated by baseband and transmitted through wireless network signals. The performance of the baseband chip will play a decisive role in the signal of the mobile phone.
Apple mobile phones from iPhone6S to iPhoneX use Qualcomm’s baseband chips; and new phones after iPhone Gained more bargaining chips in negotiations and sued Apple for software patent infringement. Apple's iPhone6S to iPhoneX are at risk of being banned from sale, and all this is caused by the baseband.