The EMUI 9.1 stable was first available on April which is fairly restricted to newest smartphone only. However, more and more Huawei and HONOR smartphones get to enjoy EMUI 9.1 which offers EROFS file system and GPU Turbo 3.0 along with the new highly efficient Ark compiler.
EROFS file system greatly increases document loading time up to 20% while saves up to 2GB of storage space. Since the file system is basically read-only, this make it harder to tamper and much more secure.
Eligible model are as follow:
Huawei Mate 9, Mate 9 Pro, Mate 9 Porsche Design, P10, P10 Plus, nova 2s, HONOR V9, HONOR 9.