Do I need to upgrade the system of the Redmi note4x I just bought?

The Redmi note4x I just bought needs to upgrade the system, and you can upgrade it to the latest version of MIUI9 system.

Introduction to the MIUI system:

Expansion: The MIUI system is a third-party mobile operating system under Xiaomi that is deeply optimized, customized and developed based on the Android system. It is also Xiaomi's first product. Since the first internal beta version was released on August 16, 2010, MIUI currently has 280 million users at home and abroad, covering 55 languages ??and supporting 142 countries and regions.

Introduction: The MIUI system is deeply customized for Chinese users based on the Android system. Such as MIUI dial-up and SMS, MIUI security center, Xiaomi message push service, application dual-opening and system clone, MIUI weather, Xiaomi cloud service, etc.

Update time: The major version of MIUI is updated once a year. On July 26, 2017, the latest version MIUI9 was launched. Small versions are mainly divided into stable versions and development versions. The stable version is updated irregularly, and the development version is updated every Friday.