Approximately 45 to 90 seconds. The userdata partition is roughly 2.5GB (for the 16GB model). If it takes longer, your USB cable or port may be causing slow speeds.
Open your scatter file in a text editor to find the linear_start_addr and partition_size values for the USERDATA section. oppo a37m userdata
Understanding Oppo A37m Userdata: The Ultimate Guide to Data Recovery, Flashing, and Storage Management Approximately 45 to 90 seconds
