The Redmi Note 4 and Mi 6 are now eligible for the MIUI 9 global beta, just like Xiaomi promised earlier this month, shortly after it announced the latest iteration of its popular Android ROM. MIUI 9 already started hitting the beta channel in Xiaomi's home country several weeks back, but it's only now that the company started an open beta for the international variant of its proprietary mobile software suite. Xiaomi already went into a lot of details regarding MIUI 9, revealing that the new firmware should manage and allocate hardware resources in a much more efficient manner than its predecessor did, consequently improving both the performance and battery life of any device it's running on.
Apart from a wide variety of backend improvements, MIUI 9 also debuts a broad range of user-facing features like a smart app launcher that's meant to predict the app you want to open depending on the current contents of your screen and your usage patterns, as well as a robust image search engine. For the time being, many of those functionalities are restricted to the Chinese version of the firmware, though Xiaomi is expected to make them available worldwide at some point in the future. For the time being, the beta build of the international version of MIUI 9 boasts a redesigned user interface that's been streamlined to a significant degree and should facilitate navigation, in addition to supporting a new Multi-Window mode. The overall feel of the firmware should also be snappier as MIUI 9 comes with new, quicker animations that are less resource-intensive, whereas it also features revamped system icons and adds some other UI elements with the goal of being as intuitive as possible.
Once you install the beta build of MIUI 9 on your Redmi Note 4 or Mi 6, you should be able to keep the software up to date with Xiaomi's dedicated system app, just like it was the case with previous variants of this Android ROM. Flashing the ROM onto a device manually will require you to unlock your bootloader, which automatically voids your warranty. There's still no word on how long will MIUI 9 be in beta before hitting the stable channel, though this experimental development phase shouldn't last longer than a few months.