The iPhone X's fast charge cable is 12 amps. A fast charge cable is a specially designed charging cable that provides a higher current output for fast charging. The iPhone X uses fast charge technology, which can increase charging speed by using a 12-amp fast charge cable, which can full the battery faster than a traditional 5-amp charging cable. The high current output of the fast charging cable can effectively reduce the charging time and improve the charging efficiency and convenience of the user. Therefore, using a 12-amp fast charge cable can help iPhone X users charge faster and improve the experience of using the phone.